hey can i download scripts form different sources and use it in my game which i may release
This all depends on the scripts. If you’re talking about things from the AssetStore, then yes i’m fairly sure all of those assets are distributed to allow commercial use, but some assets may vary as to licensing on how many seats each license allows (seats == how many computers you are allowed to use the resource on before you need to acquire additional licenses).
As for scripts on the internet. That will vary, again some scripts will be free for use commercially, some may require crediting, some may not. Others may not be available for commercial use, you will have to check around at the places that you source your scripts from.
Hope this helps.