There are so many factors that drive CPM / CPC rates: categories, channel, ad placements and publishers, device, and many more.
And even if you simply want to target all the online audience in India without any other targeting parameters, the rates will still vary based on the placements, the agencies, networks, and platforms that you will use.
Example, GDN has more expensive rates than ad networks. And across hundreds of ad networks, they have different rate cards for India even for remnant traffic.
When you use a DSP like Bluagile, your CPM rates depend on how much you want to pay. The higher your max CPM bid, the more traffic you will get. Even bidding for traffic will not get you the exact CPM rates as they fluctuate daily based on supply and demand. Your CPC rates from DSPs will highly depend on the CTR of your creatives.
If you are curious to know, launch a campaign on Bluagile targeting India and set your max CPM bid to $5 and let it run for 2 days. In two days, you will get insights as to how much people are paying for individual impression. Take note the rates fluctuate daily depending on the demand and supply.