I am interested in learning music keyboard in Hindustani Style using sa, re, ga, ma, pa. I understood the playing of white keys. . . but, confused with black keys. . . can any body help me in this regard

They are the sharp keys, they raise the notes 1 / 2 an Octave higher.

Adults often come to the point in their lives when they want to explore new hobbies. One of the most common hobbies adults pursue is learning to play the piano, and I have heard about free piano lessons which are available online
http://www.freepianolesson.com/

Please learn Harmonium by the style of Indian Classical Music.