I'm going to reject a $200 dollars ring from my mom
Why would you want to reject such a generous gift?
I don't like people who give gifts out of pity and hope to better their image
That would be a mean thing to do. It's rude to turn down a gift. You don't know why she gave it to you but you don't want to disappoint her.
You're just trying to make me feel sad so that I'll accept it.
No, I'm trying to help you understand that your mom may be giving you this gift out of a place of love, not pity. Your mom is giving you a gift, and you should thank her for being so generous. Even if she is just doing it for selfish reasons, it's still a nice gift and could help you out in the long-term.