Hi…,
Can I use the free version of Unity to develop and Publish web games without pay any money ? or I must buy Unity Pro first ?
After you earn 100000$in one year with unity free then you must buy unity pro.
Thats not correct.
If the entity owning and using Unity has a yearly turnaround of 100k USD or more it must buy Pro to publish anything with it
Has nothing to do that you did the generate the revenue with Unity or not
But if you / your business don’t generate a revenue of 100k per year, you are free to use Unity free to create games and publish them 
Thanks for the explanation didnt know that it works like that
what this equal in USD ?
that is in usd
100k = 100 * 1000 = 100’000 USD
“k” is only short for “a thousand”. So 100k = 100.000. An that’s in USD.
Or in other words: If you’ll have to ask about how much you are allowed to make fo far and what the revenue or turnaround per year is you’ll probably be on the safe side for the time being. 