Connect Normal calls to Asterisk Server [closed]

Solution 1:

Asterisk is a PBX. It can manage and route calls coming from one media to another for example, from IP (SIP) to PSTN or viceversa.

First of all you need to have connectivity to PSTN media. To achieve that you will need a hardware adapter to connect to the physical media.

There are hardware cards and VoIP Gateways that can connect to digital connections (T1 / E1) like these and these.

Digium and another vendors also have analog cards to connect to traditional analog lines like these.

About government regulations, is usual that if you want to sell phone services then you have to set up a company and request a license as voice provider. I believe that in your country it is regulated by The Telecom Regulatory Authority Of India