As u all know tata sky waited for 6 years to get transponders from GSat10 Satellite but as they did not get the transponders by mid 2013 so they decided to shift to MPEG4. They would have given rent of 1 million dollars to ISRO per month for using GSat10 which comes to around Rs 6 crore if i calculate dollar at Rs 60 to a Rupee.
Now they are investing 900 crore to move to MPEG4 which means had they got transponders from GSat10 then they would have paid this much money in rent spanning 12 and a half years t use that satellite.
Now as per my calculations after investing so much on MPEG4 Transition, Tata Sky will not further invest to pay for rent to get transponders from GSat10 right now. They will use GSat1 0 once INSAT 4A dies in next 2 to 3 years.
This is my detailed examination. As there is no point investing in GSat10 now as by investing in MPEG4 they will get sufficient space for new chs and making more investing will not be good for company funds