Oracle/DB

Oracle offers a complete, integrated set of application development tools that support any development approach, technology platform, or operating system. Oracle PL/SQL Developer Certified Associate is industry recognised certification which helps in career opportunities as application developers. You can also do Oracle Database Administration (DBA) certification also to take DBA career.
You can also do similar professional courses for DB2 and SQL servers also which are equally popular RDBMS.

If you are planning to be an application developer, you must do courses on both Oracle and .NET.

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

You are advised to do either hardware or software certifications along with BCA to enhance your employability, based on your interests and preferences.

You can join any of the following institutes:
SQL Star International Limited
e-gain.co.in
SEED Infotech Ltd., Mumbai
Core Database Systems

I am of the opinion that DBA certification be done after few years of software development experience. You may have difficulty to start career after DBA certifications without experience.

Being a B.Com graduate with a Diploma in java, I expect a minimum of 10k per month. Assuming you have a very good knowledge in java, you can jump up to 40k in an year or so.

M.Tech, MS can be a nice option but these are tough. Start looking for certification courses like that of Cisco, Oracle, Java, Juniper, Red hat. This can add expertise and can help you to earn good.

You are in a great shape. You have basic knowledge in fundamentals of computer. You should pursues B. Tech from CS or IT or else pursue BCA . Learn programming languages in demand or learn networking or database depending on your interest. Best of luck.