If you were to do M. Tech/ M.E course in CAD/ CAM from any reputed engineering college it would be the best choice from the point of view of placements. If you consider 1-year PG Diploma course and shorter certificate courses in CAD/ CAM the institutions may not always be organizing placements, but you would be able to get jobs if you have a good academic background. It would be advisable to review the admission notifications for CAD/ CAM courses in the prominent dailies and to get first hand feedback about the placement prospects from the respective institutes.