That will be way too much in France's favour too. AAE/MN will want their jets to be fully made in France, ie 100%, due to strategic considerations. So France benefits from most workshare during R&D, to the detriment of DRDO, and will still make all their FCAS in France. While India will only end up license producing FCAS with a bit more ToT. So, you can see that simply license producing the FCAS once it's ready will be a better alternative, pretty much a reason why FGFA was junked.
I don't think a $50B R&D bill, with most of the output in France, will be acceptable to India.
The only workable alternative I can think of, regardless of whether it's realistic or not, is India does most of the R&D using Indian manpower at significantly lower costs, and India and France produce 100% of their own jets, 50-50 workshare on export jets. So the bulk of the manpower heavy work where most of the salaries go will have to be carried out in India, including writing most of the source codes, the production of TDs, prototypes and LSPs, under a JV company based in India, followed by years of flight testing and debugging. Work on the engine obviously, and exotic electronics and software, which is not as manpower heavy, can be carried out in France. This will ensure the greatest of cost efficiencies.