Please take some dollars with you when you go to India. The exchange of rupees in India does not accept RMB. In addition, in India, you can use a credit card, visa or master, but you can't use UnionPay. Even if it is not a credit card but a debit card, the card must have a visa or master logo, and only the UnionPay logo is useless.
As for bringing cash into and out of the country, it generally does not exceed $2,000, but no one will take care of you at all. I took more than 4000 dollars with me in my wallet when I went to India this time, and no one checked it at all.