Has to be amphibious
Has to be able to handle rough terrain
Has to be able to go up a 60 degree slope (much like the m4 Sherman)
Has to have a full 2 plane stabiliser for being on the water
Has to withstand a shell that can pen 254mms at 60 degrees from 600 meters
Has to have a crew of 5 (radio operator driver gunner loader and commander)
Has to use the t15e1 cannon
Has to have a commander gun (coax mg is optional)
Has to be able to go in jungle terrain
Has to have detachable pontunes
Has to have angled side armour with RHA (rolled homogeneous Armour)
Has to have a pike nose with no less than 150mm composites
Lastly has to be mass produced like the is-7 was
And a side note is has to look cool