You need 4 cameras, and 4 rendertextures. Assign each rendertexture to a camera. Create 4 materials, and assign each rendertexture to a material. Create 4 planes, and assign each material to one of the planes.
Or use Camera Viewport Rect setting which allow you to output camera only to the part of the screen.
So create 4 cameras and set 4 different viewports.
hello folks,
i want to thank you all for answering me, I really appreciate your suggestions, I really like this community , reading on it this week and found a lot of useful info for a newbie like me!!