The insertion of 13 leads to LR imbalance at root. Note LR imbalance can be corrected by :
1. Rotate the node(which is in 'R' side) anticlockwise.
2. After step 1, we will get LL imbalance, therefore rotate clockwise to balance it.
After this, placed the balanced portion on the remaining tree, and adjust tree(i.e greater value on right side and smaller values on left side).
Refer Below pic for answer: