I am a Nigerian and I have a UK tourist visa for 6 months. It was issued to me on 8/3/17 and will expire 8/9/17. I would like to visit Tbilisi. Do I need a visa to enter Georgia?
As stated by Timatic, the database used by airlines:
Visa required, except for Passengers with a valid visa issued by an EEA Member State, Australia, Bahrain, Bermuda, Canada, Cayman Isl., Falkland Isl. (Malvinas), Gibraltar, Israel, Japan, Korea (Rep.), Kuwait, New Zealand, Oman, Qatar, Saudi Arabia, Switzerland, Turks and Caicos Isl., USA, United Arab Emirates or Virgin Isl. (British) for a maximum stay of 90 days
The UK is an EEA state, so because you have a valid UK visa, you do not need a Georgian visa.
At the Georgian border, just present your passport open at the page with the visa