I really want to know about the consequence of giving following command, on solaris 10 (sparc.)
What would be effect of this on whole system and services running on system and what commands will be required exactly to get back the original perms .
I recently tried above command but I am unaware of what issues will this command cause on running system,
Don't do it. If you're asking for the reason I think you're asking you will not gain any more reasonable security. (I don't think the kernel would allow you to overwrite the permissions of / anyway).
Rule #3: If an attacker gains a shell, regardless of privilege level, you've already lost the game; rebuild.