I want to pay some tax for this year before 1/1/2018, how can I do this through tourbotax

I already paid income tax, but want to pay some tax for stock gain to avoid penalty for insufficent tax pay

You cannot.  There is no need for you to do that through TurboTax.  If you want to pay federal tax go to the IRS site:

https://www.irs.gov/payments/direct-pay