What are Jim and Bob trying to solve?

Jim is so happy after finding three solutions to a problem, then he texts Bob this :

Bob, I have found 3 solutions for your problem. I do not know whether these three are the only solutions or not, but I am sure there must be less than 15 solutions.

1A,1C,2C,2E,3A,3B,4E,4F,5B,5D,6D,6F
1A,1C,2D,2E,3B,3F,4A,4B,5E,5F,6C,6D
1A,1C,2E,2F,3B,3E,4A,4B,5D,5F,6C,6D

Bob then replies:

Thank you Jim, your solution works perfectly.

Addition to make the puzzle clear :

2 Days later, Jim texts Bob.

I have found all the solutions, it has exactly 11 solutions,
but I hope you find the other solutions yourself

What are they trying to solve ?

I think it is

Planting 12 trees on a 6x6 field such that not more than 2 trees lie in the same straight line.the Apparently, the Number of solutions might turn out to be 11.

The problem they are trying to solve is:

How to place 12 points in a 6x6 table such that each line and each column contains exactly 2 points, and that the bottom half, the top half, the left half and the right half all contain 6 points each.

• Still wrong, almost right, because the solutions must be less than 15 Commented Sep 23, 2016 at 8:15
• @JamalSenjaya I tried harder. Commented Sep 23, 2016 at 8:18
• your last edit is still wrong, because with your problem you will find more than 15 solutions. Commented Sep 23, 2016 at 8:24
• @KeyurPATEL Nope Commented Sep 23, 2016 at 8:33

The puzzle is:

Placing 12 points in a 6x6 table such that each row and each column contains exactly 2 points and diagonally contains 1 or 2 points.

• Good start, but the problem is more complex than that. Commented Sep 23, 2016 at 9:50
• Ok, i will try.. Thank you for a nice question..Upvote for you..
– KSR
Commented Sep 23, 2016 at 9:51