When was PSLV used for the first time?

The Polar satellite launch vehicle (GSLV) was used or launched for the first time by Indian Space Research Organisation (ISRO) on 20th September 1993. It was a failed mission. The first successful mission of PSLV was in 1994. You can read about the GSLV Mk III – A Comprehensive Overview of Heavy Lift Launch Vehicle in the given link.

Further readings:

1. Indian Space Research Organisation [ISRO Notes for UPSC]
2. Mars Orbiter Mission (MOM) – A Complete Overview of Mangalyaan Mission