so sad to hear about your problem i am deeply regretted.
HERE IS WHAT YOU NEED TO MAKE SURE
1. was your gas conncetion valid ?
2. was your cylinder that exploded brought from the proper gas agency ?
3. were you using the proper regulator, burner and pipe supplied by the gas agency ?
4. did the delivery person fitted the cylinder or some one from your family did it ?
5. and lastly did you called the emergency number of gas agency when you smelled gas or caught fire ?
if answer to all the question is yes then you can file a suit against the gas agency for supplying the defective cylinder and claim for the dmages suffered by you and expenses done on the treatment of your father.
you can also settle your claim with the gas company but as far as my experiance says such case are always decided in the court.
so i would advice you to approach the local lawyer, file a suit as soon as possible and claim the damages.
and yes mr hardeep said it right that our LPG conncetion comes with 40 lakh insurance cover but 99% of us do not know about that.
but the advantage with filing suit for damages is that you will get 40 lakhs + the expanses done by you on medical and re settlement.
hope that helped. be strong may god help you.