Java

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.

Indian IT industry is slowly losing it's prime position because of global economical conditions and outcry against outsourcing. Creation of fresh jobs in the industry has reduced to single digit. Salary are stagnated for the last few years. Industry prefers B.Tech CSE/ IT and MCA graduates who are ready to be deployed on the projects easily without much effort. Therefore, you are advised to look for opportunities in mechanical engineering only.

Software development career is a better option for you as IT industry prefers ECE or EEE graduates for Hardware & Networking roles. You can start with Java certification. You may also do any RDBMS development certification so that you can get job in any Apps development company.

To learn web designing, you should first learn HTML.To learn software development languages, you should first learn C language.

If you are a beginner try for 'Java in 21 days'. You can get an online copy of it for free.