Explained here.
How to apply for Rushil Decor rights issue?
Once you either receive the RE’s from the company or purchase it from the market, you can apply for the rights shares using Netbanking ASBA, you can check the process in this post . You can verify your entitlement on the website of the Registrar & Transfer Agent .
You will need to enter your demat account’s Beneficiary Owner ID which is a 16-digit number while applying either on the RTA’s website or through Netbanking ASBA.
When you apply for rights shares you will have to pay Rs. 12.5 per share.
This goes to the shareholder who sold the RE’s to you. Consider it as premium paid to acquire rights to apply for the issue.