Engineer

Both are very different fields and have good scope considering that you have an engineering background marketing will be easier for you and it has good job opportunities

Graduate Diploma in CAD is a excellent value added diploma for Mechanical engineers if they plan to pursue career in design. It is a neiche skill wih opportunities in specialist design firms. Nowadays lot of MNC are outsourcing thier design work to Specialist design firms and IT firm with Engineering vertical. It is a good career option.

Of course this will help an additional qualification always be helpful in getting a good and desired Job.

operation management best for you.most if engineering student opt this specialisation.

Hi
To start with you have to score A+ in grade 10th and then choose pcm as the stream. once you get that, start your preparation for jee mains either by coaching or by self study. This will lead you to EEE branch.
All the best and hope this answers your query.

B Tech IT is a good branch with lot of openings in IT & ITES industry. Concentrate on your studies and achieve good results, you will able to pick up good job.