We have two mysql servers, 1 as master and 2 as slave (using GTID replication 5.6.21)
Currently we take full back from master server from Mysql enterprise backup
We will be performing an activity to make slave as master and master as slave
Wanted to know if there is any harm if we take backup from newly made slave (which was master earlier)after switchover?
Are you asking if it is okay to backup the slave instead of the master? If so, yes, that is fairly standard practice. The main risk is slave drift, where your slave gets out of sync from the master. So if you want to be safe, you could run pt-table-checksum on a regular schedule to detect any differences on the slave vs the master.