How to block permissions tab for certain users? Is there a way to block users who are allowed to edit users roles from seeing the "permissions" tab?

Can this be done without code?
This cannot be done without code.  If you take a look at user_menu() you'll see that access to both of those pages is determined by the administer permissions permission.

To block access to one but not the other will require you to implement hook_menu_alter() and change which permission is checked for one of those pages.