Gift Received from father in Law

No. Its tax exempt u/s. 56(2)(x) of IT act.

1. As per sec 56(2)(x), any gift received where the monetary value of such gift or cash amount exceeds Rs. 50,000 during the year then the entire amount will be subject to tax under the head Income from other sources. 
2. However, the above provision will not be applicable if the gift is received from relatives. 
3. In your case, father in law will be considered as relative for the purpose of sec 56(2)(x). Hence Rs. 15 lakhs received from him will not be subject to tax during the year. 
Please correct me if the above solution has an alternative view.