Need your opinion here guys

[Zeromn]

So at work my regional manager asked me to take on certain project at work, so basically run the project.

So my boss is fine with it and encouraged it.
My manager said to me that I should tell the regional manager that I don't have time and I shouldn't do it. He said he will tell the regional manager that I did it so he won't question it.

This is not normal from my view of things. Why does he want to dull me ?

Would love to hear your view

[MMM]

1. REGINAL MANAGER
.
2. MANAGER

Which is in the number 1 spot?

Haters watch who the Reginal Manager likes, wants to do the job. Do what your Regional Manager said. You can use the excuse, I DON'T WANT TO GET FIRED if your Hater Manager gets angry, or don't say anything and JUST DI IT! 

[TracerX]

Depends if you actually have time for it. In a corporate environment, everyone takes care of their own ass. It won't benefit your manager if you take on extra work. If you have the capacity you can accept the job.

Next time you can just first accept the work and then you just inform the manager "hey, I'll be doing this task from the regional manager xyz", if you want it. If you first talked about it with your manager (which probably you did) you're throwing the judgment call on them. Thus he decided not to let you do it.