Here is the list of top 10 countries which has maximum vegetarian percentage in the world.
India's vegetarians make up around a third of India's population, and two
thirds of the world's vegetarian population.
India -- 29% - 40%
Italy -- 7.1% - 10%
Ethiopia
Lebanon
Turkey
United Kingdom -- 2% - 12%
USA -- 3.3%
Singapore
Jamaica
Israel -- 2.6% - 13%
NOTE
the list is according to https://collectively.org/article/the-10-most-vegetarian-countries-in-the-world-in-order-of-meatlessness/
The perentages are according to wikipedia. But the percentages are based on different years.