I would like to know is there any provision for parallelly copying data from main table (one schema) to different schema table... Yes
...without hampering current traffic?Maybe, maybe not.
If my machine/storage can handle 60 concurrent busy sessions, then running a parallel operation that needs 16 workers is not drama.
Conversely, if my machine/storage can handle 12 concurrent busy sessions, then running a parallel operation that needs 16 workers is going to fry it.
But copying data in parallel is as simple as:
insert /*+ enable_parallel_dml append */ into target
select /*+ parallel */ ... from source;
Full discussion on the feature here
https://docs.oracle.com/en/database/oracle/oracle-database/21/vldbg/using-parallel.html#GUID-3E2AE088-2505-465E-A8B2-AC38813EA355 You can also use Resource Manager to place a limit on how much impact a user/session/etc can have if you want to have "safety limits". You'd need to liaise with your DBAs on that