Following is mentioned in ISROs annual report....
India’s advanced communication satellite, GSAT-10, carrying a total of 30 communications transponders in C, Extended C and Ku-bands as well as a two-channel GPS Aided Geo Augmented Navigation (GAGAN) payload operating in L1 and L5 bands, was launched by European Ariane-V launch vehicle on September 29, 2012. The satellite was later placed in the intended geostationary orbital slot of 83 degree E longitude. The transponders are in the process of augmenting the capacity of the INSAT system while the GAGAN payload is intended to provide the Satellite Based Augmentation System through which the accuracy of the positioning information obtained from the GPS Satellites is improved.
Indian National Satellite (INSAT) system, established in 1983, is the largest domestic communication satellite system in the Asia Pacific Region with Nine satellites in operation INSAT-3A, INSAT-3C, INSAT-3E, INSAT-4A, INSAT-4B, INSAT-4CR, GSAT-8, GSAT-10 and GSAT-12. The overall coordination and management of INSAT system rests with INSAT Coordination Committee.