How to know UE supports SA or not in Network?
I think i found:
3GPP TS 36.306 version 15.4.0 Release 15 103 ETSI TS 136 306 V15.4.0 (2019-05)
This field indicates whether UE supports standalone NR, as specified in TS 38.331 , and includes the supported NR
bands as defined in TS 38.101-1  and TS 38.101-2 .
I also found in actual UE capability as below
If supportedBandListNR is there in UE capability-> UE support SA for those band
If only rf-ParametersMRDC is there, and not supportedBandListNR, the UE support NSA only between LTE and NR, SA not supported here.
Even reporting supportedBandListNR is not enough. This is the indication of per band capability which is common to SA & NSA. UE needs to report the corresponding SA combos to indicate the support of SA to network. Network will use these combos to redirect/HO the UE to SA network.