You have to visit website of the NCD company, for example, Muthoot finance or whichever NCD you are interested in. You must contact that company on phone and ask them to send the application form on your email. You have to print that form, sign and send back to that company by post/courier. Now a days you cannot apply for NCD directly from your bank or broker. Alternately, you can download the application form from the internet and fill it, sign it and visit renowned bank like govt. bank or HDFC etc. where you have account with and sit with the bank official and get the form registered by them physically. It is better to contact the company directly. In case of Metro cities, where the company has branch office in your city, you can contact branch and they will happily assist you fully for NCD investment in their company.
I have checked ASBA on HDFC bank & BOB - Can't see the NCDs - only rights issue can be seen.
Thanks in advance