15lacs given to my brother please give suggestion please

You can file a suit for recovery of money on the basis of Promissory Note provided the signature is genuine. You can claim the Principal, interest together with the Court expenses including the advocate fees. You can examine yourself in proof of the execution of Promissory Note. 

The limitation to file a suit for recovery on the basis of Promissory Note is 3 years. You should file a case before the limitation period of 3 years.