Borewell rehabilitation in Bangalore, Karnataka - Need help in finding a reliable bore services vendor

We have 2 bore wells in our apartment complex. Both of them seems to have dried up - one 6 months back and the other a week back.

Some people suggested to go for camera testing to make sure that these bore wells are really dried (we already tried stone drop method). In case these are dried up we need to go for new bore well drilling.

We are looking for a reliable vendor. We got some quotations from some private vendors but not sure how to judge them. The prices seems to vary a lot atleast for camera testing and hydro fracturing.

In our area (Bellandur, Bangalore) the water level seems to be quite deep. The borewells in our apartment are around 550ft deep (which we need to test) but in neighboring apartments most of the borewells are more than 800ft deep.

Any techinical specifications that we need to ask from these vendors like:

1. Video testing: Are there different in types lke resolution?
2. Hydro fracturing: Like max depth that can be treated; max water pressure,
3. Drilling: What type of drill m/c suitated for such deep digging
4. Casing type?
4. Any other information like making of chamber etc.?

Also could you please suggest a good electrical resistivity surveyer?

Thanks a lot for supprt,

Best Regards,

Pradeep