Is there any way to count the blocks in a faster way? I am an estimation engineer and normally i have building drawings with different blocks . is there any guide line available to calculate the number of a specific block available in the given drawing quickly?? 

There are several ways to do this:
 
* the BCOUNT command
* select block, SELECTSIMILAR and the Properties window (Ctrl+1)
* dynamic table - DATAEXTRACTION
* the BLEGEND (picture legend) utility
* and probably also other ....
 

Thank you so much my dear.... for your reply...

Also try QSELECT, in which you can specify a Block name to look for.  And an AutoLISP routine could easily be written that would do that, with the User supplying the Block name.  If they might sometimes be dynamic Blocks, it would need to be done differently than if not.