Statement 1 is Correct: The Indian National Space Promotion and Authorisation Centre (IN-SPACe) was established in 2020 as an autonomous, single-window nodal agency under the Department of Space (DOS). Its primary mandate is to promote, authorize, and facilitate the participation of private entities in India's space sector, acting as a bridge between ISRO and private players.

Statement 2 is Correct: In May 2024, the Chennai-based space startup Agnikul Cosmos successfully launched the Agnibaan SOrTeD suborbital rocket from its private launchpad in Sriharikota. This historic mission marked the world’s first flight powered by a single-piece, fully 3D-printed rocket engine (a semi-cryogenic engine named Agnilet).

Statement 3 is Incorrect: Skyroot Aerospace is a prominent private Indian startup that develops its own independent launch vehicles (the Vikram series) and engines. However, it does not develop fuel or engines for the Geosynchronous Satellite Launch Vehicle (GSLV). The GSLV is an ISRO-owned heavy-lift rocket, and its liquid and cryogenic stages and fuels are developed entirely in-house by ISRO (e.g., via the Liquid Propulsion Systems Centre).

Therefore, the correct option is C.