He is probably Shankar's younger brother who is a undercover police officer to nab the dacoits...Maybe he thinks that dacoits ie., Bhawani killed his brother and Phulwa is involved as told by Thakurs...Thats why he is here to take his revenge but in a legal way by trapping the dacoits and later arresting them...
I don't know why but I have a gut feeling, he is related to Parviti, probably connected to her past,
If I'll come up with a random story then maybe THAKUR had another son who Parviti was in love with and got married but the THAKUR killed his own son & Parviti gave away her son to some lady and now he is back to find out more...