Mate, the Harriers have hardly a decade of life in them with the new upgrade carried out on them. Plus there's hardly 11-12 of them left now, they have limited capabilities and their basic role is land-attack and are not multi role capable like the Mig-29Ks. We have already bought 45 Mig 29Ks and I think the Navy won't be buying anymore. Admiral Mehta said that by 2022 IN plans to have an air arm comprising of 300-400 aircrafts. And believe me, by 2022, even the Mig 29Ks that we have bought now will be outdated. So, the bulk of air arm will eventually comprise of N-LCAs, NMMRCA and probably a 5th genr. version of the PAKFA or FGFA. So, ultimately it will be 3 platforms. Plus by the time we get the IAC-3, which will probably be a CATOBAR carrier, we would require heavier, advanced and more capable fighters than the N-LCA, hence the reason we are going for the Naval MMRCA in the near future !