From the context, the order inside these groups does not matter.
Hence, the problem is on Combinations.
So, the ANSWER is : in .. = = 360360 ways.
Explanation
First, you form the group of 3 from the set of 13 people in ways.
Then you form the group of 6 from remaining 10 people in ways.
Finally, you form the group of 2 from remaining 4 people in ways.
After that, you just have no choice: the last group of two is just defined by a unique way.