1 silo in arihant can fit 3 k15 missile, so it may be able to fit 4 bramhos or 5 nirbhay considering their diameter (0.6 and 0.52). While k15 is 0.75 in diameter
Nobody will try nuclear testing in space as there are chances of malfunction in rocket. If the rocket explodes while taking off or in mid air, what will happen to the nuke?