iCloud backup

gaganjain wrote:

That is only if The option is active. Right now the option is disabled and I am not able to click button

Probably because one of these haven't been satisfied....

1. Upgrade your iCloud storage plan.
2. Reduce the size of your backup.
3. Delete any data that you don't need.
4. If you still need help, contact Apple Support.

See -- If you can't back up to iCloud or restore from iCloud backup failed - Apple Support.

Did you review the link I provided above?