I don't believe the Indian mints issue either, apart from the occasional set of commemoratives. The best bet will be to wait for the 1 and 20 rupees to release and buy the group on ebay. You'll probably have to pay more than the coins are worth though, especially once accounting for shipping.
Yeah, I figured that. My grandson was born in 2019 and is 1/2 Indian, 1/4 white and 1/4 Japanese. Had to get two Japanese sets.
I just found out this month that Japan offers VERY little of their sets outside their own country. Only 100? 500? Not sure. So you're quite fortunate (or rich) to get one. LOL.
Actually bought it on e-bay from a Japanese seller...had to get two sets, one for each of the two emperors that year!
When Japan produced their first 100,000 yen gold coin, it was made available only though a lottery to Japanese citizens or some such. My mother-in-law got me one that I still have.
As mentioned before, India has not issued complete coinage proof sets for around 40 years now. There are commemorative proof sets (I think 7) for 2019 that have been announced and released, but the Indian mints are famously slow at producing and sending the products. The themes range from the 150th birth anniversary of Mahatma Gandhi to the 100th anniversary of the Jalianwala Bagh massacre. Your best bet would be to wait until 2021 and then buy one on eBay or similar.