Thank you Dynamox  I got  $ nas_replicate -modify iscsi_rep1 -name iscsi_rep2 -max_time_out_of_sync 90 it is working
Now the celerrareplications are happening to the every 12hrs,But I want to change this to 24hrs. Please let us know where can I change the schedule. I am using unisphere,array is NS-480.
How to change the celerra replication update time