What is full form of RT, RL, RW and ER

Full form of ER in CBSE Result

ER: This year, CBSE has removed 'Fail' and used ER which stands for Essential Re-appear

The full form of ER in CBSE marksheet is Essential Re-appear.

cbseresults.nic.in, CBSE 10th Results 2020: सीबीएसई मार्कशीट पर लिखे RT, RL, RW, और ER का क्या है?

The various full form related to CBSE results marksheet are : -

Full form of RT - Repeat Theory 
Full form of RL -  Result Later
Full form of RW- Result Witheld
Full form of ER - Essential Re-appear Full form of CBSE - Central Board of Secondary Education