Upvote:1
If you book separate tickets for your flights, then in most cases you have to transfer the bags yourself. Even if the separate tickets are on the same airline or partner airlines, the check-in agent for your first flight is not obligated to check it through to the destination of your second ticket. Some airlines will do this as a convenience, but you should not rely on it.
When you need to transfer the baggage yourself, you must clear immigration in the airport you are transiting through, in order to claim your baggage. Therefore, you will need a transit visa in this case.
That being the case, you should expect that you will need a transit visa for India. VFS quotes the price at 34500 KRW plus 5400 KRW service charge, but this is wrong; you should actually pay much less than this as an Afghan passport holder (India charges no visa fee to Afghan nationals for transit visas, so you should only pay the VFS service charge and a small consular fee).
Note that the transit visa is valid for 15 days from the issue date, and allows a maximum 72 hour stay.