The first time I flew into India (Delhi), I was surprised to see so many better-dressed (Indian) passengers from my flight literally running to the duty-free and buying shopping carts full of foreign whiskey; Johnny Walker, Dimple, Laphroaig, JD, Wild Turkey, etc. It puzzled me because I thought alcohol was legal there, so why the rush? It turned out the only place you can buy non-Indian-made liquor is by-the-drink in the bars of the tourist hotels (a shot of Johnny Walker Blue was $20 USD equivalent in my hotel bar). The package stores can only sell Indian-made hootch.
And when I bought a bottle of the local stuff and tasted it, I realized why all those guys were so keen on taking taking advantage of the duty-free to stock up.
I don't know the time period you were referring to but there is no bar on imported liquor in India. Duty free means exactly that -cost with taxes are substantial outside.
India is the largest whisky drinking country in the world and while quality varies across price points, some of India's top single malt whisky's are among the world's finest routinely appearing on the best lists. One of the main drivers for an India-UK trade deal is for more scotch to be sold at lower duties in India.
"Some of the World's Best Whiskeys Are Coming From India"
https://www.foodandwine.com/india-single-malt-whisky-8666916