Whatever we order again will take 3 years to arrive, whether it is the Rafale or the MKI.
But we need 2 new squadrons each of Rafale and MKI to be ordered or the IAF will become smaller than the PAF once the Migs exit.
I would go for two more squadrons of Su-30's (but work towards upgrading the whole fleet as had been discussed earlier). Start up one or two private lines of the LCA Tejas MK1A - with the intention of ramped up production and eventually taking HAL out of the picture altogether.
And I'd wrap up that old, rumored, large scale Rafale production deal (~150 for IAF, ~50 for INAA) but with the slight twist of 36 more Rafales immediately as a G-2-G deal since locally produced ones are probably far in the future (and when the big deal is signed, we make 36 less than we originally would have).
Last of all, I would keep an eye on the Russian PAK FA program; and once they finally complete them and roll them out, I would look into purchasing a few squadrons to make up numbers and start getting our pilots familiarized with stealth fighters.
I think a mixed bag solution like this would help India maintain decent numbers while fielding a high quality force. But out of all of my suggestions, the Tejas solution is most crucial; that's the only way we'll make up the sheer numbers shortfall any time in the near future. And once we have LCA's in decent numbers for Air Defense, that'll free up the heavier and more powerful fighters to undertake offensive operations.