All the consultancies in India are equally bad. They will rip you around 1Lac rupees and you will end up doing PR process yourself anyhow.
If you can read/write english, post message on this forum then why do you need a consultant ?
No the consultant doesn't have any magic lamp nor he can do anything to speed up your PR processing.
Every piece of information is available on the CIC website and on this forum, you just need to do a quick search.