Depends on strain of plant width & height when grown, any training or style of grow method used ?
This can ultimately lead to how many plants which can be grown.
Doing a search on the internet will provide loads of answers to this very question... more than likely any where between 4 to 16 plants depending on strain type & grow style.
A larger light such as a 600w or even 1000w would be better in a tent that size or considor a half decent reflector.
Watts per square foot & lumen per square foot greatly increase's yield so they say