caste certificate

I am working in a Government Job in state electricity board. I have joined in the year 1992 based on SC Caste reservation. One of my relative alleged that I am from backward class and not from SC and asked for my caste certificate through RTI. I have given my caste certificate and subsequently department enquiry was formed for my caste scrutiny. The DM mentioned me as of backward community. My query is SC certificate was issued to us from 1950 -1995. Later on it was found that we are not from the said community and thereafter Backward caste certificate was issued to us. By that time I have already joined the service based on SC reservation. Many of my relatives are either working or got retired from govt post. My uncle have already retired as a govt official based of SC caste certificate. Will I be prosecuted or any action can be taken against me in service. Since I have not forged any document nor given false statement for obtaining sc caste certificate. Since we were issued it before my birth itself and my college and school have sc caste written over there. Also by far department has unable to find record of My appointment letter mentioning I got SC reservation nor the advertisement for Job through which i was selected.