As per the Recent Tweet of CBIC, which clarifies the ambiguity of extension of the due date of GST Return for the month of February 2020. The Extension has been given for the returns due in the months of March, April and May 2020 i.e. returns for the supplies made in the months of February, March, and April 2020.
Source: https://twitter.com/cbic_india/status/1242417395387346945