Let's guess

He is supposed to be a secret agent.

He was kidnapped.

Perhaps he fled and to avoid being caught again he jumped in a stream or was pushed into in an attempt to kill him. He is wearing the same clothes as on the first day.

The lady saves him.

And then...

Manish is wearing different T-shirts. So, for several days Karan is living with this girl. If he is wearing same type of clothes, perhaps the girl already knows him and might be working together. They might be living at the same place even before. Or simply they went for shopping and Karan has chosen the same type of shirts.