CES production function profit and supply function
Hint: Solving for the FOC's assumes that the solution is interior, in this case, that profits are positive and smaller than $\infty$. I would recommend you to derive the cost function $c(y)$ and then study its derivative. If the marginal cost is always smaller than the price of the good (probably it is assumed to be 1) then producing more is always better and profits are unbounded. However, if the marginal cost is always larger than the price, then the optimal is to produce nothing and get zero profits. 

Hope this helps.