I need to specify specific IP range for Nmap scan, for example:
192.168.1.140 - 192.168.3.255
If I do it like:
192.168.1-3.140-255
IP addresses like 192.168.2.7,192.168.3.7 won't be scanned (only 140-255 in 4th actet).
You will probably need to specify this as two different ranges. Nmap will accept as many target specifications as you like on the command line. Here's one way to do it:
nmap 192.168.1.140-255 192.168.2-3.0-255