Well good for indians if it thinks it has all the ingredients to confront china. As for annihilation, india has NFU theoretically, but even if there is a war (if i take your opinion as the general perception and view of indian leadership). It won't go nuclear because firstly india will need a very strong reason for world community something like chinese army is at doors of delhi, because going nuclear for losing disputed regions will not be accepted by world at large. Secondly India has already stated it to be bilateral issue, going nuclear will make it global the moment india signals its intentions.
The only way India and its military can restore its status quo on LAC and confidence in public is to take back its lost territory with full conventional force or remain like modi as nothing happened.