Complex sentence: The SLBM version of missile will arm the Arihant class submarines of the Indian Navy.However, DRDO revealed last year that it is also in the process of developing another variant of Agni-VI missile.
Split into simpler sentences: The SLBM version of missile will arm the Arihant class submarines of the Indian Navy. Moreover, DRDO revealed last year that it is also in the process of developing another variant of Agni-VI missile.