My answer is 24.
0 state--> 1 state : 2 ways
1 state --> 2 state: 4 ways
2 state -> 3 state: 6 ways
3 state -> 4 state : 6 ways
4 state -> 5 state : 4 ways
5 state -> 6 state: 2 ways
Total Number of transitions: 2 + 4 + 6 + 6 + 4 + 2 = 24 WAYS
Please correct if I am wrong!