My company provides me access to 401k, and I am contributing the maximum allowed in that 401k. In addition I also have Roth IRA (I qualify for it because of income less than $193000). Recently, my company has said now we have option of regular 401k or Roth 401k. Now, I am wondering if I can contribute to all three accounts? I know I would be subjected to maximum limit of 401k, but is it still allowed?
Yes, you're allowed to contribute to both a Roth 401k and a regular 401k; it's fairly common to do so for the purposes of diversification. You can also contribute to a Roth IRA, assuming you're under the income limits.
Note that your employers' contributions to your 401k (like a match) are always pre-tax, not Roth.