Answered on February 09,2018
'TM' stands for Trademark and 'SM' stands for Servicemark. The use of TM and SM symbols notifies the public that the company is claiming exclusive ownership of the trademark and can generally be used by one who has filed a trademark application.
The ® symbol, can be used only once the trademark is registered and the registration certificate is issued. Also, you may use the registration symbol only in connection with the goods and/or services in respect of which the trademark is registered.