Can we block the IP range for particular web site using .htaccess ?
Yes, you can. Just add following line:
deny from x.x.x.x-x.x.x.x
If you want to block just on IP range, you can do it using following:
deny from 192.168
It will block the access for 192.168.0.0 to 192.168.255.255
Kailash