Here is the solution.
Open your Nero burning ROM, select DVD Video option, Click on NEW
Drag and drop ur first Video_TS folder and burn to Image burner ie hard disk. It'll create a .nrg file. Give appropriate name for it.
Follow the same procedure for ur second Video_TS file. Give appropriate name for it too. YOu have to do it separately .
Now you have two .ngr files.
When you create two .nrg files, Open ur nero vision, select DVD option and say Add video files, in file type option select ALL FILES. locate ur ,nrg files and import these to nero vsion. Rest should be easy. You can create chapters etc and burn them to DVD. Hope this helps. But remmeber you should have much hard disk space for it