I am making one website in which i will upload flaash games

U  can use games legally if owner provides u the widget ( like code) which u can host on ur site just like giving a link in this case owner will get deserving credit. But i guess this will be very tough n time consuming if u wanna go all legal

Yes You have to fallow copyright  because it help to avoid any type of problem regard your website rank and money. You can hire a freelancer who expert in this field. 

I recently also worked on the creation of a site for betting apps, and I really liked the implementation on this site https://gambling-apps.in/betting-apps/cricket-apps/, good apps, while playing even won something) from there a few games, it seems, without problems with the rights.

For me, sports betting is almost my main source of income. So for me it is very important on which platform I do it. I have been doing it for a long time and I haven't met any better than https://betwinners.in/hi/ . Everything is simple and reliable here, all the major events are at my fingertips. What can be better? I recommend it!

Flash is a multimedia programming language developed by Macromedia Inc. (now Adobe Systems) that supports animation, video playback, and sound recording. It was introduced in 1996 and has since been used to create animations for web pages, interactive applications, digital books, computer-based training courses, and corporate presentations. Its popularity stems from its ability to display complex graphics using few resources and its ease of use.