When you arrive from outside India in DEL you can go to the international transfer desk and get your onward boarding pass. For Air India its very straightforward as their counter is always manned with multiple agents. So in your case you go over there and get a new AI boarding pass and then look for the HIX. If JAL has not interlined your luggage, AI can send someone downstairs and retag your luggage, I've had this situation this March. They just printed a new baggage tag and gave me the receipt of that one after collecting the receipt of the old tag.

Other airlines in DEL are a different topic. If your onward flight is more than 4 hours away the transfer desk agents may not have anyone available to contact in the back office and that is when you have to wait near the desk till someone from the airline comes to work.

JAL in Tokyo may be a different topic with the Visa. On their records it looks like you are terminating in DEL, so they may want to see a visa documentation.Proof of onward journey should be sufficient, but you never know.