The dialogues of Dadi are such that you fervently wait for her to come on screen and use her acid tongue. Otherwise this is not a comedy film as such; you will not find comedy everywhere. It is a family drama.
But there is one line where Nakul (Ayushmann Khurrana) tells his brother on discovering that their aged mother is pregnant: 'Bas apna kamra chahiye. Tu tere ma-baap ke beech zyaada nahi so sakta tha?' (You keep asking for your own room; why couldn't you sleep in between your parents?) The entire theatre was roaring in laughter.
Another instance would be when Dadi says to herself about her son, who works as a TTE in the Railways, 'Sarkar mein kaam karta hai par sarkar ki baat nahi sunta. Har jagah, TV aur cinema mein condom ka ad lagake rakha hai.' (He is a Government servant but he cannot obey the Government's simple advice to use condoms.)
One more. Jeetendra (the TTE) has a friend in Meerut named Chawla. His son, who has divorced and remarried, is infertile. One night, during a family wedding for which the Kaushik family has come, this son starts to dance on the stage. Then Jeetendra's (pregnant) wife tells him, 'Ab isko sikhao.' Earlier Chawla himself told him to do that (i.e., since Jetendra is having a baby, he can teach the infertile to have a baby). Every now and then there were some lines like this where everybody (all were Indian) was laughing loudly.