I am sure the phrase should be "On a turnkey basis." "Turnkey" is one word. "Basis" is with an I, not an E. A "turnkey" project means a completely finished project, ready to use, with nothing at all left to do. The analogy is with a house, that has been built complete in every detail. In order to move in, the only thing the buyer needs to do is turn the key in the door. "Basis" means the ground rules, the fundamentals, the understanding. "On a turnkey basis" means "The agreement is that this project must be absolutely complete in every detail."

Thank you very much!!!

First, I think it should be "on turn key basis". The grammar used here looks like a resume or a description of a job. It's "note taking" English and doesn't follow proper grammar rules. My guess is that the company has a specific way of financing and executing projects. However, since it's still unclear, I can't give you a definite answer. Sorry, but it isn't very clear what that means, and I don't think it's an issue of your English ability as much as the writing is just not clear.

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Correction: On turn-key BASIS.