Java

JAVA has nothing to do with Big Data, but I would advise to take a DBA course before get into Big Data.

Java is no doubt the most widely used application programming language. You may start with less or average pay scale as java developers are given value once they gain experience.

It may be difficult to get job in Switzerland directly. Lot of Swiss BFSI companies have captive development centre or outsourcing IT partners in India. You may work with such companies and then seek an on-site assignment to work in Switzerland.

Hello Karthik
If you are seeking for job without degree than you have very less chances, but you can build your own business and also became a freelancer developer. It has many pros in terms of financial view, if you are good in delivering good software.
But, if you are looking for a job than I personally suggest you to join an institute for advance certification because with course they also provide placement assistant, so it will be beneficial for you to find a job.
But, select the institute wisely.

I think Java and networking have better scope in future.
1) For many years Java language is providing the best technology solution to the industry and also it is the most secured platform.
Also, you can see that Java is the core technology for android. Android also has a good scope in the current scenario.
2) Networking is one of the best fields because we have to do something new to get better and secure mode of communication. Also, after CCNA, you can clear CCDA.

Indian IT industry prefers B.Tech CSE/IT, MCA, BCA, B.Sc CS/IT graduates for technical roles. Therefore, you may face challenges in getting technical roles in IT companies. You are advised to do MCA for a meaningful IT career.

Java, for sure. If you know Java from deep you are an open weapon. Try to learn php, Python and Django language along with Java.
All the best.