1. Go to https://mailchimp.com/features/domains/
2. Sign up and fill your details.
3. Verify Your E-mail address.
4. Select Free plan from below.
5. Enter Your Name details, and your company name.
6. Select No when they ask if you have website.
7. Add your address and other things.
8. Fill details and complete survey.
9. Now click on set-up your website.
10. Click on pencil icon near the domain like xxxxx.mailchimp.com
11. Select Find New Domain.
12. Select your desired domain.
13. And fill details.
14. Add your Card or PayPal account. ( Don't worry your amount will not deduct )
You have got the new domain for free for 5 years.