 It is an Indian Earth Observation (EO) satellite, to be placed in a geostationary orbit of around 36,000 km.

Application
 With this satellite, which has high-resolution cameras, we can keep a constant watch on our borders, monitor any changes in the geographical condition of the country.
 The EO sats are apparently for benign uses such as land and agriculture watch.
 But their images also have a very important use for the military, for keeping an eye on the borders.
Context

 ISRO making preparations to launch GISAT1 in March 2020.