I have over 3k reputation on stackoverflow. I have edited few questions but i never got any reputation from it. Is there any restriction on who gets the reputation from edit?
After you reach 2000 reputation, you no longer recieve reputation from editing. This is because your edits no longer have to be reviewed; they are applied immediately.
When you have less than 2000 reputation, other users review your edits in the suggested edit queue, and you gain rep when they're approved.
See the privilege page for editing others' posts for more information.