There is no point of comparing M.Tech and MBA. Both are specialised degrees and have values in their respective grounds.
M.Tech would be more of a subject matter specialist, whereas the MBA handle product sales and marketing project management, IT process, human resources, consulting and customer service management.
M.Tech is suitable for a product based industry where technical skills are required whereas MBA is more suitable for a service and customer oriented industries.
So if you are interested in technical aspects then go for M.Tech with the specialization you are interested in and if you are interested more into sales and marketing then go for MBA. Inorder to crack both exams and to job top institutes you need to crack the respective exams. For M.Tech you need to crack GATE and for MBA you need to crack CAT.