Try x=-1: 1-3-3+11-6=0 so x+1 is a factor.
Use synthetic division to find the cubic:
-1 | 1 3 -3 -11 -6
1 -1 -2 5 | 6
1 2 -5 -6 | 0 = x³+2x²-5x-6
The constant -6 has to be the product of factors. So if we take x=2, the cubic becomes 8+8-10-6=0, so x-2 is a factor. Use synthetic division to find the quadratic.
2 | 1 2 -5 -6
1 2 8 | 6
1 4 3 | 0 = x²+4x+3 = (x+3)(x+1)
Full factorisation: (x+1)²(x-2)(x+3). The zeroes are -1, 2 and -3.