Question: I try to fill CGT schedule for an individual tax return however i am unable to find Main residence exemption under Exemption Type.

Answer: CurrentlyLodgeiT doesn't support main residence calculation in automatically mode. For this time,  please fill the capital gain manually with required values, please see below. 

Exemption or rollover code is just the statistical field that goes to ATO and doesn't affect the calculation.

Reference note from the ATO -

Partial exemption - there is no appropriate field on the form, so there is no chance for the user to report exemption amount along with capital gain/loss.

ATO advice about "Partial Exemption" - 

Reference link - ATO advice about "Partial Exemption"