plug our own consensus in any one of ethereum client?
Take a look at Parity's Pluggable Consensus feature:
You can either choose to experiment with the consensus algorithms Parity ships with (Ethash, Instant Seal, Aura), or write your own and plug it into the framework. (See the
engines part of their Github repository for an idea of how to do this, together with the wiki page above.) Note that everything's written in Rust.
I don't think Geth provides anything similarly pluggable, though there are various tutorials on how to get Clique working (e.g. this one).