Suitability of hydro - fracturing for low yield bore wells in Chennai, TN - Need consultants

We undertake construction services in Chennai. Recently in one of our projects we had an extremely rocky sub soil with lot of big boulders. When we made borewells we could hit soft soil patches, but the yield has been reduced now from the initial level.

Details of Borewells:

1. Location - Our site is located at Chelli Nagar, near Camp road junction, selaiyur, Chennai - 600073. There is a lake located within 750 meter radius.
2. Diameter  - 6" borewells (2 Nos) both having soft spots at about 70-80 ft depth. 4 1/2" borewells (5 Nos) out of which 3 are dry and 2 having very low yields 
3. Depth -  6" borewells are 300 Ft and 4 1/2" borewells are 200 Ft depth
4. Casing used - Heavy grade PVC casing pipes erected till the rocky sections of sub-soil ( about 20')
5. Time / date of construction.
     6" -Bore No 1 - June 2008
     6" -bore No 2 - May 2009
     4 1/2" bores- June to Nov of 2008

Will Hydro fracturing help? or will blasting help? Is there any consultant in Chennai offering the mentioned services? What will be estimated costs of the same?

Visweshwar .C