Query on gift to parents

I'm an adult salaried person and my mother is a housewife. I want to gift INR XX to my mother and she will then fix the amount in a FD. Do I need to club the interest of FD with my income and do I or my mother need to pay tax for this?

My mother has a valid PAN but total income from different FD is less than 50K.

Also, please suggest if there any upper limit of the gift amount.