The statement S1 is true and S2 is false.
The given polynomial is: $x^6+1$
The highest degree of the polynomial is 6
So all the burst errors with Length<=6 will be detected. So
S1:This generator can detect all burst errors with a length of 5 bits: True
S2:This generator can detect some but not all burst errors with a length of 6 bits.is false as all errors of length 6 can be detected..