what's the call

[jomatiky]

Bases loaded, GB to 3B, he catches the ball and while transferring the ball out of his glove bobbles it and never get control and is run into by R2 who was trying to avoid 3B

[Radwaste50]

he makes the play and while transferring the ball out of his glove

What play? does he tag a base? a runner? simply field a ball? is he trying to make a throw?
Did you judge him to be the protected fielder?
What was called? What wasnt call?

[jomatiky]

fields the ball and attempting to throw to a base he bobbles it. Didn't realize it was so hard to understand

[nopachunts]

You didn't indicate what F5 was going to do after the transfer.

It's a HTBT situation but from putting your two posts together, I probably would have interference. If in your judgement, R2 prevented F5 from retiring either R3, R1, or BR, you could get one of them to.

[celebur]

fields the ball and attempting to throw to a base he bobbles it. Didn't realize it was so hard to understandYes, it was. From the OP, I had interpreted "GB to 3B, he makes the play" to mean that F5 fielded the ball and got an out (most likely the force out on R2 by stepping on 3B). This clarification completely changes that.

I think this is very much HTBT. For this to be interference, there still needs to be a legitimate play for F5 to make, and after making such a bobble, there wouldn't be many options left for F5. Also, F5 bobbled this "on the transfer", so F5 is not in the act of fielding the batted ball any more, so I may not have interference at all if I didn't see intent by R2 (who in the OP was actually trying to avoid F5). Even if I do have interference, I think it highly unlikely that I'd get two outs on this.

[patrick s]

NFHS 2011 SB Rules Book, 8-6-10c: The runner is out when the runner interferes with a fielder attempting to throw the ball.
ASA 8-7-J2 Same wording.
NCAA SB :12.19.2 same
I don't have LLSB so I can't address that.

[patrick s]

If in your judgement, R2 prevented F5 from retiring either R3, R1, or BR, you could get one of them to.

This is not a 100% accurate statement. Fed uses the wording: If this interference, in the judgment of the umpire, is an obvious attempt to prevent a double play and occurs before the runner is put out the immediate succeeding runner shall also be called out.
ASA drops the word obvious, but calls out the runner closest to home.