How will install SSL Certificate on IIS Server? Explain with any of the ssl provider standard

To purchase a SSL certificate you need to provide the CSR

There are free online tools available to generate CSR

for eg below

https://www.digicert.com/easy-csr/openssl.htm

The SSL provider will give you a .key and .crt / cer file once you send the CSR and make payment

In IIS server Go to administrative tools

administrative tools>> Internet information Services Manager >> Complete Certificate Request 

open the crt / cer which you have received from SSL provider and provide the domain name as friendly name

 Considering a wild card certificate as example *.domainname.com