Sure these ships have spent tons of time already serving and thts why they have been retired, however i dont recall either of them being involved in any major accidents etc. China bought 3 diff classes of hulls just to study them - without even having a formaly announced CVG development program. Both Indian carriers were leagcy carriers having spent tons of time already in service with other navies. Even the Gorshkov is old. The only brand new carrier IN will get is when it going to operationalize its first small IAC. A Kitty hawk could give IN the platform to study for (a) to study a big/supercarrier - also a nuc-powered carrier (b) to make a platform to study and train personnel for CATOBAR ops
If India wishes to purchase the USS Kitty Hawk to 'study' it, I think the US would cheerfully sell her, and then proceed to laugh all the way to the bank as the saying goes...
While the vessel might not have been involved in any major accidents, she is, at least in parts, over 50 years old, having been initially laid down in 1956. With that kind of timeframe, the design is not longer current in terms of carrier construction, damage control, etc. Additionally, IMO the US would remove the most interesting and up to date systems (like radars, electronics, computers, ESM, etc) and likely the catapult system as well.
Also, the design is a conventional, as opposed to nuclear-powered carrier. As such, it would give India no additional expertise or knowledge in terms of designing a nuclear-powered vessel of their own.
If the sale were done, the likely outcome would be that India would have a large, floating hulk to would likely be too expensive to modify and re-commission, nevermind keep operational.
-Cheers