Need a rule sect.
 

I was wondering if someone could lead me to the section of the rule book that would explain this scenario: A1 shoots the basketball while the shot is in the air A2 pushes B1 does the basket if it goes in count or is the basket disallowed?

It looks this scenario is about team control. Rule 4, Section 12. Check out the case plays, too.

Rule 6-7
Any time a live ball enters the basket from above, it's a goal. The questions are:
1. What causes the ball to be dead?
2. What are the exceptions to #1?
3. Do any of the exceptions apply to this situation?

To determine #3, you'll need to know when team control ends. (4-12)

My take
 

In order for the basket not to count it would have to be a TC or PC foul. Since the has been released on a try for goal, TC ends so count the basket. The action between A2-B2 would be treated as a common foul, bonus would be shot if in effect.