Hi,
I have configured my domain ('iitminc.com') in cloudflare and changed the DNS server names. So Main domain works fine! I have added 2 subdomains ('student.iitminc.com' & 'iitmwebservices.iitminc.com'), in cloudflare, as A records.
In Goddady Main Domain had a different IPv address from subdomains so I copied them in cloudflare.
Now, when I try to browse my subdomains, they show 404 error.
Please advise if I need to do any other change.
Welcome to the Cloudflare Community. 
A 404 indicates that your origin server does not contain the requested resource. You will want to set your subdomains with this error to 
DNS Only while you work with your host to ensure that your origin server is performing as expected and serving your content correctly over HTTPS.
Thanks for a prompt reply!
I tried your suggestion and moved to DNS only option, so the subdomain works on http at least.
As per Godaddy, subdomains are working correctly and since I have changed the DNS sever names to the one provided by cloudflare, they won’t be interested in troubleshooting at their end.
Godaddy doesn’t entertain any request once you move to some other provider 
I guess I’ll have to troubleshoot myself 
Any further suggestion would help
You might see if you can get HTTPS working on your subdomains with a Cloudflare Origin CA certificate. You will see an Unknown Issuer warning until you reactivate the 
proxy. That is expected.
I checked settings on Host server and found an option to enable SSL and that did the trick.
Thanks!
This thread can be closed now.