I guess battery went dead, and my trany went into a limp mode.. all PRND432 are lid, and its stuck in 3rd or 4th gear. R is fine. How to get out?

I think it depends on whats causing the limp mode. When it was throwing tranny codes turning the car off and back on took it out of limp mode untill i passed 1st gear. But after I got my timingbelt/waterpump replaced I had to clear the codes manully before it would leave limp mode. Try getting it scanned with a vag-com or obdii tool to see whats causing it and if you can simply clear it.

The tranny should not go into limp mode if the battery dies, if your tranny is in limp mode, you need to get it scanned and have a look at the codes. By the sounds of it, you are going to get a powertrain databus code, no communication with the TCU, or implausibile signal, something like that. I would say, scan and clear the codes, see what comes back, then repost here

I had the unfortunate LIMP mode on my car when I was testing some upgrades on the ECU for the engine and for the tranny.
Not a fun experience, however i found that it is either related to the ECU or the TCU. clearing codes will not help, sometimes just patience but will fail again.
I dont think is related to the battery either.
But I will start by reading the codes and see where that leads you to.
Let us know how it goes