Yes, you can file RTI to Controller of Defence Accounts (CGDA).
Controller General of Defence Accounts (CGDA) is one of the oldest government organisations in India operating under the Ministry of Defence of India. CGDA is the cadre controlling authority of the Indian Defence Accounts Service. CGDA is a "Public Authority" as per Section 2 (h) of the RTI Act 2005.
You can file the RTI application by addressing the same to the designated "Public Information Officer (PIO)" either Online or by Offline mode and by paying the prescribed fee.
To know more about the procedure to file RTI Applications Online for Central Govt. Department, please refer https://onlinerti.com/how-to-file-rti-online-for-center