In India, when an investor purchases some units of gold through SGB. Who holds the purchased units? Like stocks purchased are held with CSDL or NSDL (as far as I have understood, correct me if I am wrong).
SGBs are government securities denominated in grams of gold. They are substitutes for holding physical gold. Investors have to pay the issue price in cash and the bonds will be redeemed in cash on maturity. The Bond is issued by Reserve Bank on behalf of the Government of India.
If you want more details then feel free to read the following website: UCOBANK official documentation