"The CPI congratulates ISRO scientists for staging yet another spectacular launch of three-stage heavy weight rocket GSLV-D6 with indigenous cryogenic upper stage and for successfully putting in orbit GSAT-6 communication satellite," party general secretary S Sudhakar Reddy said in a statement.
ISRO had launched the satellite, having an indigenous cryogenic engine, on August 27.
The feat is second one for ISRO scientists in using the indigenously made cryogenic stage after the January 5, 2014 launch of GSLV-D5.
The earlier one had propelled India into an elite group of countries boasting of the homegrown complex cryogenic engine and stage after twin failures in 2010.