GoAir — no show for 1 passenger

Address:

Kolkata, West Bengal, 700006

In one pnr, there are two travellers. If one of them cannot travel due to some last moment crisis, can the other traveler travel alone on the ticket for two without paying any penal or additional charges?
There was no scope to cancel the ticket of the passenger (No show status) beforehand who could not travel.
My main questions are;
1) whether the person travelling alone does have to pay any charges for the person who could not turn up, because they were issued a single ticket with same pnr.
2) what would be the answer if the ticket of one passenger is cancelled earlier, not at the last moment.
3) which option is economically beneficial for the traveler — earlier cancellation or "no show".
In all cases they have single pnr ticket.