Both, and primarily to secure the vital sea lines across the Indian Ocean. India is now a major trading nation and so access to the seas is just as vital to them as it is to nations like the United States. Carriers represent power projection, a ready means to project airpower across the region to places where national interests are threatened. China and Pakistan are two such primary challengers to India. Say China projects its navy into the Indo-China or East Indies waters that could threaten to cut off or interfere with commerce. Without the carrier, India is in little position to respond. But, with a carrier, likely working in close cooperation with the US Navy, India can directly influence events to its favor.
Relations with India and the US are getting better, which is something I've long wanted to see happen. Their air force is outstanding and I've never seen any reason why the two most populated democracies on the planet could not and should not become excellent strategic allies.
So, I'm glad to see it happen.
Ken