Call to a Land line in PSTN network

Is it possible to make call from softphone to land phone in PSTN netwotk using Asterisk Server?

Yes. No real difference from doing it with a hard SIP phone, except that the latter is likely to be more reliable (issues with the phone, not with Asterisk).

Could I suggest that you need to read the book at, as I think you need to do some background reading on how Asterisk can be connected to the PSTN.

Softphone assumed to mean a SIP phone emulated by a PC.

Pedantically, Asterisk is both client and server.