You cannot restrict the world to use only RIP or EIGRP, if some network administrator using RIP and Some other is using EIGRP, then how end to end communication will be possible.?

Hi Tahir

Yes it is possible.

As you mentioned, if some network administrator using RIP and some other is using EIGRP. The end to end communication is possible with the help  of Redistribution. All routing protocols support a feature called Redistribution. With the help of it , we can exchange routes between different routing protocols.

For example :- As shown in diagram. Router 2  will perform redistribution between EIGRP and RIP, because Router 2 is the common router , on which both EIGRP and RIP protocols are running. You can read further about Redistribution, it is an interesting and important topic. 

Hope  it will be helpful.

Thanks