How to create a subdomain on another server

I have a server with the domain name inventiva.co.in which is a dedicated server purchased from OVH and running a wordpress based website on the domain www.inventiva.co.in

Now I want to run elgg on a sub-domain which would be community.inventiva.co.in

But I want to run this subdomain community.inventiva.co.in on some other server which again I want to setup using hestiacp.

This new server is from some other company but will have a complete separate ip address.

I am not able to understand, how to setup this.

So the infra that I want is

Inventiva.co.in- server a- ip a.a.a.a.

community.inventiva.co.in- server b- ip b.b.b.b.

My DNS is hosted on my primary server with the ip a.a.a.a

Can someone please let me know the step by step process?

Regards

You just create the appropriate DNS A record for the subdomain hostname in your DNS on the first server using the IP of the second server.

What is causing you confusion?