You can buy Non-Convertible Debentures (NCDs), bonds, and tax-free bonds on Kite the same way you buy shares. Simply search the company's name in the universal search bar, and the available debentures will appear.
These instruments trade in the secondary market with a T+1 settlement cycle. You can also buy them using ASBA.
You can find detailed information like maturity, coupon rate, and bond type by visiting nseindia.com. Search for the company name and select the series. Bonds are listed in the N series from N1 to N9 and NA to NZ.