if 10000 records loading in the table using SQL LOADER.
In that when 5000 records gets loaded, the server gets down.
in this case,whether that particular records gets committed or not?
In this case data will not be loaded in the database once database broughtup it will rollback all the uncommitted transactions.
According to my understanding, Yes. SQL loader normally uses bind arrays & INSERTs (+commits) the data once the bind array is full. You can check for yourself.
SQL*Loader Control File Reference