How long can I apply again as a tourist visa to Uk after I finished my 6 months visa. I am here right now at UAE for 2 months and I want to go back again to UK.
You can apply immediately, there is no "cool off" period, or 90/180 day limit like for Schengen.
However, you have to convince the UK immigration officer dealing with your application that you are not attempting to live in the UK via successive long term visits - if they suspect this, you will be denied and banned.
Your visa may be cancelled and you may get a long-term ban on visiting if your travel history shows you’re repeatedly living in the UK for extended periods.