@kumar , check the job controller (filter by this client name) and see if another job for the same subclient is running.

the newer job will resume once the prior job completes.

I have check and there is no another job running only file level incremental backup is working fine rest all SQL job failed.  

@kumar , is the job getting that error NOW or did it happen earlier (perhaps when other jobs were running)?

You can enable this option:

Control Panel > Job Management > General tab, select Queue jobs if other conflicting jobs are active

This will cause these jobs to queue up until the previous job(s) complete.