Science

If you want to switch to B.Tech in CSE immediately, you would have to discontinue your current studies in EE (Diploma), or you could complete your diploma and then opt for an M.Tech in CSE, or B.Tech in CSE, whichever you prefer. Two regular courses running simultaneously may not be allowed, as it has legal implications.

As you said that now you are purusing your B.Sc in HM, but you are willing to do MBA in the same field.
As I know, you will get the same results after that also, but if you want, then you can go for M.Sc in HM, or you can do it through distance also.

You just have to qualify GRE, TOEFL, learn basic German language and apply for scholarship form, if you need it.
Well, it is a free advice, you can opt for anywhere 'just believe in yourself & prepare for it'.

Just keep calm, and take career guidance by any an experts. And, just don't worry, because everything happens for the best. It is my experience and not only me, every one knows this.

Either he may go for a job or higher study. I suggest him to do at least PG. It will give him a great satisfaction and respect in the life then if he wants, the best is to go for Ph.D. If he qualifies JRF, he will get INR 12000-14000 as a research scholarship for a maximum period of 5 years until he completes Ph.D. If he wants to do a job then there are vacancies for Bank PO and Staff Selection Commision, NDA, CDS, but don't go for a private job at this stage.

There are many courses that are available for students to choose from. Some of the courses that are presented for students to go for after the completion of their graduate studies are:
Master of Technology in Biotechnology
Integrated Ph.D courses
Master of Philosophy in Biotechnology
Master of Science in Applied Biotechnology
Master of Science in Zoology (Animal Biotechnology)
Master of Science in Biotechnology
Master of Science in Industrial Biotechnology
Master of Science in Marine Biotechnology
Master of Science in Medical Biotechnology
Master of Science in Plant Biotechnology

It should be easy to get a job with a technical Ph.D., and the pay will be higher than with a Master's degree. However, for each 100 Ph.D's produced, there may be only 1-2 openings for faculty members each year. This leads to fierce competition for these slots.
Most Ph.Ds will go on to an industry. Industrial and government research labs allow Ph.Ds to continue doing research, but many Ph.Ds will do highly skilled (non-research) work in the industry.

You need to complete HSc in order to opt for a Bachelor's degree.