II am not able to login in iclaud

There is a hard limit to the number of new iCloud accounts you can create on any device. That cannot be changed. There is no limit to the number if existing iCloud accounts that can be used with a device though. So use another Apple device to make your AppleID and iCloud account, then use that to sign into that existing iCloud account on that iPhone.

Three is the maximum number of free [Apple ID accounts] you can have on an iPhone. You can't create more whatever you do.