Giving her serious image a toss, Tabu goes all out as the loud, opinionated but essentially well meaning elder sister who will move mountains, manipulate people, break hearts just to make sure her younger sister gets the best husband possible.
Sharman Joshi: Rahul
He thinks it was love at first sight for him and Nisha. But it was stage managed by Rajeshwari all the way through. Too late he realizes that even their break up has been stage managed by big sis. But now he will manipulate the situation to his advantage.
Vatsal Sheth: Yuvraaj
Every mother-in-law dreams of a son-in-law like him, he's that handsome, well behaved in short perfect. So you can't actually blame Rajeshwari for choosing him over Rahul.
Yuvika Chaudhary: Nisha
This pretty girl has a heart of gold that beats for the poor and the uneducated. But it beats fastest for Rahul. And her heart is shattered when her beloved elder sister deliberately tears her away from the man she loves.
Rajeshwari (Tabu) exemplifies the quintessential Indian middle class woman with the aspiration and ambitions to reach the next higher social stature in her society. The film is based in a B-town centre of India and carries the mentalities and the true essence of the "Great Indian middle class".
Toh Baat Pakki Rajeshwari is married to Vinay (Ayub Khan) a bank cashier for the last 7 years. She has two adorable children Geet and Suraj 6 and 4 respectively. She has always been the driving force in the family and her dream is to get her sister Nisha married to the most suitable boy within their Saxena community. Rajeshwari is against the dowry system and therefore the propositions to find a suitable match within the given scenario is not very promising but she is determined to do so.
As the story unfolds, Rajeshwari with the fate of chance finds a good Saxena boy studying engineering and has prospects of a promising future. Rahul (Sharman Joshi) is a good proposition for her sister and ceasing the opportunity she gets him to move into her house as a paying guest. Of course, here money is not discussed but the only discussion is about his prospects and views on marriage. However, when Rajeshwari learns that Rahul is not interested in marriage, she smartly devices a plan to bring her sister and make them get to know each other...and almost confident that once he meets Nisha there is no turning away and Rajeshwari's predictions are right.
Nisha's innocence and simplicity are a rarity in this day and age, which makes it impossible for Rahul not to be bestowed. They fall in love. Rajeshwari is happy. Marriage is fixed "Toh Baat Pakki."
This is all set; preparations are full swing, till one day Yuvraaj (Vatsal Seth) comes to Rajeshwari's house. Yuvraaj is also a Saxena. He has his own business, he is waiting for his house to get built...Rajeshwari's can't believe her luck! This is a better prospect.
The story takes twists and turns where Rajeshwari tries to set up Nisha with Yuvraaj. Rahul finds out through Nisha about Rajeshwari's tricks. He now needs to alter this situation without getting Rajeshwari suspicious of his acts. Will he be able too? Will Nisha misunderstand Rahul? Will Yuvraaj learn of Rahul's tricks? Will Rahul marry Nisha? Will Rajeshwari outwit them all?