You can’t launch the Brahmos from the standard 533 mm torpedo tubes of a sub; you would need a VLS for that. Which would requiring modifying your (small) Diesel-electric subs; which is also why the Indian navy has continued to buy the smaller Klub cruise missile for its subs.
About surface-ships, it’s more or less the same problem. Your average missile boat or corvette can mount about four of them and even then won’t be able to exploit it fully due to the limitations of their onboard sensors. About aircraft, the only TACTICAL aircraft which can deploy the Brahmos is the SU-30 and theoritically the F-15 too.
Sounds like a missile their military can grow into!