The protagonist of Behen Hogi Teri, Gattu (Rajkummar Rao) is an average boy — below average at academics, a bit timid when it comes to standing up to his parents and with no future prospects to boast of. But the one thing he’s sure of is his fondness for his neighbour Binny (Shruti Haasan) who he is a supposed rakhi brother to due to the mentality of the locality that these both reside in.

Mostly it's about Gattu needing to find the courage to stand up to Binny’s family — and his own — and declare his true feelings, which takes painfully long to happen. He just stands by and silently observes Binny’s engagement to NRI Rahul (Gautam Gulati) and allows a huge misunderstanding about her alleged affair with his best friend (Harry Tangri) to snowball.  Ranjeet and Gulshan Grover appear as local thugs who respond to inter-caste romances with honour killings. If they stand on one side of the war lines, Darshan Jariwala, who plays Gattu’s father, stands on the other side, desperate to assert his authority in this neighbourhood.

The story gives an insight into the traditional mindsets of people in the nawaab city of Lucknow and how these love-birds find a way into love amidst all of this.

Will they be successful in marrying each other?

What happens when their respective families come to know?