Traditional 401k vs Roth 401k for employee match

Hello,

My employer is offering a 6% match into a 401k plan that I attend to follow through with. I plan on putting 100% into VTTSX target dater index fund.

Now the question is do I do a Roth or traditional?

I already personally have a Roth IRA through fidelity with FDKLX index fund in there.

Thanks!