Yes, you can file RTI to South Delhi Municipal Corporation (SDMC).
SDMC is one of the Municipal Corporations in Delhi, India created after the former Municipal Corporation of Delhi (MCD) was divided into three ("trifurcation") in 2012 into South Delhi Municipal Corporation (SDMC), North Delhi Municipal Corporation (NDMC) and East Delhi Municipal Corporation (EDMC). MCD came into existence on the 07/04/1958 under and Act of Parliament. As a result, SDMC is a "Public Authority" as per Section 2 (h) of the RTI Act 2005 and comes under its ambit.
You can address the RTI Application to the designated "Public Information Officer (PIO)" of the concerned Department of the Corporation by paying the prescribed fee.
To know more about the procedure to file RTI Applications to Departments in Delhi, please refer https://onlinerti.com/how-to-file-rti-online-for-delhi