I didn't make a value opinion of PVC one way or another. I believe it is unsafe if one is going to seriously burn an aggressive propellant. If one is going to do something outside of what is recommended in safety suggestions/rules, they are responsible for the damage they cause to property, people or themselves. If one owns the launch site that is off the beaten path of commercial airways, they can do whatever they want. Last I read years ago is that type of airspace was rare at that time and probably rarer now.1. There is a vast amount of rocketry going on that has nothing to do with TRA or NAR.
2. The PVC matter is open to dispute. If you are at a resonable distance from the pad, it is not an issue. You use what you have.
3. The OP is in India. Not everone in the world have the luxuries we have in the US.
Last I heard, India is a pretty densely populated country. Something like 1.408 billion. Probably not much space to do significant HPR unless one is shooting a single use rocket over the ocean.
I've been active for some time and well aware there are intelligent groups that experiment outside organized rocketry. They have the smarts and the space to do it. I envy them and wish them well in their endeavors. Kurt