Season 3 follows all of the children who have now grown up, and Himani who is pregnant again with a boy, whom they later name Bobby. Avatar is busy with work, while Sunny still indulges in pranks and experiences typical high-school problems. Dolly is now dating the basketball captain Ayaan, and Rohan experiments with his career choices at college. Nikki enrolls in a playschool, and they all help with raising Bobby.
With a fifth Singh child on the way, Himani demands a larger house. Dolly and Ayaan audition for "Romeo and Juliet" at their college; Ayaan gets the lead opposite a school trustee's daughter who has a crush on him. Sunny and Roli Aunty pull an escalating series of pranks to see who gets the last laugh. When the family is almost done packing, Himani reminisces and tells Avatar that she wants the family to stay in their home.
The basketball team blame their losing streak on Dolly and Ayaan's relationship, so they fake a breakup in hopes the team will relax. Sunny starts acting on his best behaviour when he thinks his parents are considering sending him to a boarding school, a misunderstanding they do nothing to clear up.
Himani convinces Pam's mom to throw her a baby shower, but the shower takes an unexpected twist when Nikki blurts out all the horrible things Himani said about her guests, making them angrily leave. Rohan and Sunny compete to go to a cricket match with Avatar.
Dolly makes an excuse to go to a graduation party with Ayaan. Rohan asks the flower-delivery girl to be his date, and she invites him to her graduation party--which is at her parents' house as she is learning through correspondence; Avatar goes to the doctor for a check-up and overhears the doctor speaking about another patient named Singh.
Himani overhears through the baby monitor that Dolly and Ayann have been secretly rehearing the play Dinku the Donkey!. Dolly got the lead role and did not want Himani to steal the spotlight. In the end, Himani stands in for a cast member who broke a leg. Meanwhile, Avatar desperately wants to fix a fuse in a gorilla cage to prove to Sunny that he's cool.
Himani and Avtaar vote on baby names for the fifth Singh child. Dolly is eager to find a quiet place to study for her final exam. The parents overhear Sunny expressing anxiety about being forgotten when new baby is born, and try to make up for lost time that they did not spend with Sunny.
The baby is one week overdue, upsetting Himani's mood. Dolly tries to help her by inducing labor, but Himani does not want the new child to be born on Nikki's birthday and overshadow her. Avatar, Sunny, and Rohan shop for a new family car, but their purchase does not fit inside the garage. Sunny is sent to buy Nikki a doll for her birthday but forgets.
Nikki's birthday invitations may not have been mailed, and so Sunny and Rohan dress up as princesses in order to entertain her. Himani goes into labour and they hitchhike to the hospital on an ice-cream truck. On the way, Himani gives birth to their baby boy, Bobby Singh.
Avatar's aunt visits to help with Bobby, but drives Himani so crazy that she asks Dolly to keep the woman away. In a box of old things Roli Aunty gave them, Sunny and Rohan find an unmailed letter claiming money is buried in her backyard. They dig at the exact location mentioned, unwittingly excavating for her new hot tub. To pay her back they put green dye in the hot tub.
The family takes a vacation to a haveli (English: historical mansion), and quickly becomes convinced that it is haunted. It turns out that they are on a prank TV show. Dolly pretends to be sick and throws a house party while the rest of the family is gone. Roli Aunty blows their cover, so they make a deal, but her parents eventually find out.
Sunny begins to like a girl at school and tries to convince her that he has a soft side. At the park, Rohan and Popi decide to have another baby race, this time using tricycles.
Rohan announces that he is moving into an apartment with Popi to be closer to college; Himani is heartbroken and not ready for such a big change. Meanwhile, Sunny discovers that Avatar is afraid of carrying Bobby up and down the staircase after he dropped Nikki years ago.
Sunny tricks Himani into building a model rocket for his science class. Avatar enjoys peaceful quiet at Rohan's apartment since the Singh household has recently become loud and annoying.
Himani returns to work at the end of her maternity leave and finds her boss is divorced and working as well. Himani has hallucinations of Nikki and Bobby. Sunny and Rohan watch over Nikki but she runs away. Meanwhile, Dolly attends the mock parliamentary session alongside Ravi; Bobby nearly causes them to lose due to his frequent crying, but they soothe him by singing their final presentation, which leads them to victory. Himani decides to become a stay-at-home mom, and Avatar child-proofs all the locks so Nikki cannot run away.
Dolly's team is on a losing streak, so new team mom, Himani, hosts a team-bonding slumber party in the hopes that they will work together to win a game. Meanwhile, Sunny starts dating a new girl, Saniya; Avatar immediately becomes annoyed by her father because he is clingy and has horrible manners.
Ayaan goes to apologize after getting into an argument with Dolly, but instead gets advice from Avatar on how to handle a Singh woman as a "Ladkiology expert". Himani overhears and instructs Dolly how to handle the situation. In the end, Ayaan apologizes. Meanwhile, Sunny avoids chores by spending the weekend with his friend Shibu at Rohan's apartment.
Sunny is just gaining popularity when Himani gets a part-time nursing job at his school. They agree to pretend not to know each other, and she uses her maiden name, Batra. Meanwhile, Rohan has to babysit Nikki and Bobby, and begins a babysitting service with Popi.
Himani throws a party to entertain Nikki and Bobby, dressing in a kangaroo costume with a pouch for her two youngest children. Avatar puts a cape on over his work clothes and calls himself Super Bijlee Man, but Himani disapproves of his meager efforts. Meanwhile, Sunny is deceived by Roli Aunty into attending a ceremony in honor of her charitable work.
Pam is directing a community-theatre play, and Dolly pressures her to cast Nikki in the lead although she failed the audition. A boy calls Avatar Nikki and Bobby's grandpa, so he attempts a youthful makeover. Sunny does a school report on a neighbor with a fantastic job and makes Rohan pose as the person for extra credit.
Avatar's aunt returns once again to celebrate his wedding anniversary, much to Himani's dismay. Things go awry when Himani and the aunt learn they are performing the same act at the talent show. Elsewhere, Avatar struggles to find the perfect gift for Himani.
Dolly wants to ace a statistics test, and asks Saahil to coach her since he earned a perfect score, but his strict, demanding teaching methods soon make her regret this. Meanwhile, Avatar's snoring is keeping Bobby awake at night, so Himani makes him sleep with Sunny.
Avatar shows Himani a rare species of termite which gets loose in the house. Himani starts contributing to Teen Today Blog under Dolly's name.
Sunny tries to find a new room for himself after Bobby is moved into his room. The termites ultimately destroy the entire house and the Singhs move into a hotel. Rohan announces that he's dropped out of college, but wants to attend catering school.