Our nuclear program is very secretive . Very few people have knowledge about full details.. my father in his last year was posted in MOD for 1 year and he never uttered a word about it...we don't need to test hydrogen bomb because now supercomputer simulate it very well.. our nuclear program has come a long way .. even North Korea have tested hydrogen bomb in 2017 with yield greater than 200kt.. with 2.5 tons warhead , the yield would be in MT of TNT... Fun fact as the members have mentioned here Agni 3 is a mirv missile, . But Agni 6 would be our true mirv with at least 5 warhead and decoys..