They could have definitely done both, but till 1991, it was all about only the public sector and after 1991 the biggest goal for the Tatas was how to get Air India back into the fold. Remember license permit raj was still in full effect and had driven away many an entrepreneur till 1991. I would have put this right up the alley of HMT, given location in Bangalore , experience in making watches and tractors(in addition to many others), CONgress gobarments in state and center, proximity to ISRO etc. ISRO could have definitely spearheaded given it’s need ( though small for itself but it was given responsibility for communication networks, since the humble radio was still called transistor across the length and breadth of the country). In 1984 when the first INSAT went up, it had solar panels to derive energy for the spacecraft. Microprocessor was invented in 1957, for which Jack Kilby even got a Nobel and by 1971 Intel had its IPO and was a public company. All memory patents lapsed by the mid 80’s which is why the Koreans could easily start memory production. Sam Pitroda, who had the foresight to establish CDOT could also have taken more interest on this foundational technology and maybe gotten the CSIR labs more involved ?