Use command line rendering, just open notepad and some code:
“C:\Program Files\Autodesk\Maya2015\bin\Render.exe” -r vray -cam camera1 -s 1 -e 200 “D:/maya/projects/project.mb”
“C:\Program Files\Autodesk\Maya2015\bin\Render.exe” -r vray -cam camera2 -s 201 -e 400 “D:/maya/projects/project.mb”
More commands and tutorial that you SHOULD read
http://www.jawa9000.com/Technical/batch/batch-rendering.htm
Then save as render.bat on your desktop - done!