can i fit reverse camera to my original columbus head ,it has rear sensors and plays dvds  ,

Yes the Columbus supports reversing camera. 

 

There are plenty of threads on here about the correct camera etc to use. 

i have a rear camera mounted and was using an an android head unit , the picture was SO poor 😟 i went back to original head unit , i need to know how to fit video feed to columbus head . i will try to search on briskoda but not found info yet , many thanks 

If you have one fitted that worked with an Android HU, chances are it's a composite feed. You'll need a composite to RGB converter.

https://www.ebay.co.uk/itm/387075546283?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=d9az2whhqnc&sssrc=4429486&ssuid=Ivbg29OuQe6&var=&widget_ver=artemis&media=COPY

 

I'm not 100% sure if that is correct, as most are to convert an existing RGB camera feed to cvbs, but from the picture it looks like its the correct way round for your use.