Does rclone works with rsync to upload just the delta changes instead of complete file change?

I have a question about rclone: I would like to know whether rclone actually uploads just the modified part of the file? when syncing it to a cloud source

The whole file.

is there anyway i could just upload the delta alone?

You can use a 3rd party binary diff tool.

Or you could use a backup program like restic (which can use rclone directly) which will do binary diffs.

Can you please provide some link reference for the same?

https://restic.net/