Please help me, if I made a complete game and I want it to sell, I have made the game in unreal engine but by using various blender assets . So will there be any problem ?
Because blender is one and only option for me to create my own game assets. And I want to sell my game so as to make money. So is it legal ?
As long you created all assets by yourself (models and textures) or used free ones, then it’s ok.
Also, make sure you didn’t break anything that might be protected by copyright or trademark like existing cars, guns, logos, sounds and music, …
If you have the rights to use the blender assets, and are following the license terms, you can certainly publish the game legally.
If you created the assets yourself, you own the rights. However - trademarks and copyright rights also exist. So if you model a character from another video game franchise, you likely wouldn’t own the intellectual property or trademark and can’t use that asset commercially.
If you downloaded the assets from a store, you will have to check the license to make sure the terms allow for commercial use. There are many different licenses that an artist or store can place on an asset - it’s up to you as the developer to know what those licenses mean and how to comply with them.
Check this link for more on licenses, attribution, and fair use