Do I need to pay any money to register for the Hackathon? No. You do not have to pay anything to anyone to register yourself for any Hackathon on HackerEarth.
Do I need to have any specific qualifications to be a participant for the Hackathon? If you love to code, you are more than welcome to participate in the Hackathon.
How do I submit what I have made for the Hackathon? You have to develop the application on your local system and submit it on HackerEarth in tar/zip file format along with instructions to run the application and source code.
Do we need to have the entire idea fully working? The entire idea need not be fully implemented however, the submission should be functional so that it can be reviewed by the judges.
How is the environment? Will your environment support any language? Will you provide any IDE and DB for us to work on ideas? You have to develop the entire software application on your local system and submit it on HackerEarth in tar/zip file format along with instructions to run the application and source code.
Does one have to be online and available for the entire duration of the Hackathon? No, one does not need to be logged in on HackerEarth or be online for the entire duration. You can develop the application on your local system based on the given themes and then submit it on HackerEarth, on the specific challenge page.
Since there is no specific technology mentioned, are there any restrictions on using number of pre-built libraries? There is no restriction to use any language, technology stack, or libraries. You can use any of them to create the web/mobile application.
Do I need to give a demo for the product that I have built? If you want you can submit a small presentation or video that demos your submission, however it's not mandatory, and only good to have. In case you are one of the winners, you might be invited to demo your application at a physical event, details of which will be shared with sufficient advance notice.
A fully developed application need to have a solid backend for data storage like SQL, SharePoint etc. since its online, is it accepted to show only the proto type of it? Yes it's absolutely fine to submit just the prototype. If you use any database like MySQL or PostgresSQL you can also submit a database dump along with your submission. However you are allowed to submit just the prototype.
If it is a team submission, does that mean all team members will have access to work at the same time? Yes, all team members can login from their account and do application submission on HackerEarth.
Who will own the IP(Intellectual Property) Rights to the product that I have built?
The IP for the main prize winner will be transferred to Sponsors to be developed further, should both parties agree to it. All participants by default retain IP as below:

All work created during the hack must be accessible to Stop the Bleed Coalition and stipulating that Stop the Bleed Coalition will not use this for external commercial purposes without consent from the participants who have created the new IP.

If you wish to pursue any commercial development in respect to this intellectual property, then Stop the Bleed Coalition have a right of first refusal to collaborate with you.

Participants will need to sign an NDA upon mutual agreement of co-ownership or transfer of IP.