$10 or ₹750 per year for most common domain extensions - example : anjanesh.com
Some others are like around $30 per extension - for example, anjanesh.digital - give or take another $10 to $20
Domains can be purchased from many providers (GoDaddy being the most popular one) but I choose mainly from : ResellerClub, BigRock, Google Domains or CloudFlare.
I use CloudFlare for domain management. It can also be managed at ResellerClub, BigRock or even Google but Cloudflare is the industry leader in this currently with the free edition being more than good enough for 99% sites and has paid tiers @ $20 a month (per domain) for even better performance for clients having online business at a larger scale