Honestly going for a bunch Super-hornets and growlers wouldn't be bad. We can raise a fleet of naval tejas mk 2 based on the similar engines for coastal defence. F-35 B's will take a lot of time to come online. But I think the f-35 bought by india would be the most advanced. F-35I capabilities along with the meteor. If only...
While Rafale is the best option, the SH + Growler combo should still meet IN's minimum requirements. The weapons compatibility with the USN and RAAF also helps quite a bit.
If Rafale doesn't happen for the navy, the F-35B also won't. It faces the same issue. But if you're referring to using F-35Bs from LHDs the upcoming LHD tender should resolve any doubts, especially if Korea gets involved. Their CVX plan is pretty impressive, they are building three of those, so a lot of new technologies would be developed by them compared to France and Italy.
In case we do go for the F-35C, yeah, it's gonna need customisation by default. Any F-35 purchase for India would need customisation.