I'm not able to get ±120V from the top power supply unit.
Any suggestions regarding power supply unit or the full circuit would be appreciated.
Thanks

 

Well... for start you can try measuring where the 120V are lost? After the bridge, before the TL.. after the TL.. ?

 

Well... for start you can try measuring where the 120V are lost? After the bridge, before the TL.. after the TL.. ?

I'm getting voltage after the bridge, on the capacitor, even before the TL (for positive only, not for the negative) but not after the TL

 

Change U2 to an LM337-T.

The problem with having an LM783 is that it is a positive voltage regulator which can only pull the output down toward the positive-power supply.

An LM337 is intended as a negative regulator which can pull the output toward the negative power supply. That's what you need there.