Accounting

Since you have only completed 12th I would recommend you to study further and get a graduation degree before applying for job in Indian Railways. To be eligible for some of the best jobs in Indian Railways, you would need a Engineering degree.
Saying that It doesn't mean 12th pass candidates are not eligible for any jobs in Indian Railways. There are Group C and Group D jobs in Indian Railways for candidates with intermediate qualification. But my recommendation would be that you get a graduation degree before applying.
Bachelor degree in Engineering with Mechanical / Electronics or communication branch would open door for better jobs in Indian Railways for you.
The jobs in Group C are:
Ticket Examiner
Trains Clerk
Junior Clerk cum Typist
Ticket Collector Junior Accounts Assistant
Commercial Clerk
Assistant Loco Pilot
Account Clerk cum Typist
Junior Stenographe
In order to get a job, you will have to clear the Railway Recruitment Board (RRB) exam. Each year Indian Railways post ads for vacancies. You will have to make sure that there are jobs that meet your qualification criteria before applying.

There are a million options you have right now:
Start with taking up job in one of these industries:
Customs department
Economic consulting jobs
Indian Economic services
Tax consultancy
Insurance industry
Actuaries
Banking sector
Financial firms
Stock Broking
Corporate finance
Audit firms
After you gain some good experience in one of these sectors, try to understand which part of the industry you like the most and then go on to pursue higher studies, since with so much competition you'll not survive if you don't hone your technical knowledge.
Once you have decided your area of specialisation you can go for:
MBA
Masters in commerce (finance)
Masters in cost control and control accounts
Masters in corporate accountancy
Masters in advanced accountancy
Masters in accounting and finance
Masters in accounting and taxation
Masters in accounting and auditing
Masters in accountancy and business statistics
Master of Business Administration in cost and management accounting
Master of Business Administration in finance
Chartered Accountant
Master of Financial Management (M.F.M. )
Master of Commerce (M.Com in e-commerce )
Master of Financial Services Management (M.F.S.M.)
Diploma in investment studies (D.I.S. )
Diploma Course in e-commerce & financial accounting Mgt.
A) E-Commerce Technician
B) Computerized Office Technician
C) Computerized Financial Accounting Technician
PGDPA Post Graduate Diploma in Professional Accounting
M.Phil (Accounting)
Post Graduate Diploma in international financial accounting system ACCA Association of Chartered Certified Accountants
Association of Chartered Certified Accountants
Certificate Course in Central Excise (CCCE)
Certificate Course in Financial Accounting & Taxation (CCFAT)
Certificate Course in Income Tax (CCIT)
Certificate Programme on Capital Markets (CPCM)
CA
CFA
FRM
CS
ICWAI
Please do not make the mistake of pursuing a Master's or a Diploma without working for at least 1-2 years.

The Bachelor of Accounting and Finance is a specialist three year full-time or part-time equivalent degree offering a comprehensive course in the theory and applications of accounting and finance.
The course involves units in accounting that allow graduates to be simultaneously recognized as accounting and finance professionals.
Unlike pure accounting degrees, the Bachelor of Accounting and Finance offers a broader understanding of financial instruments, institutions, markets and systems. It involves the study of financial decision-making under uncertainty, which is applicable to banking, financial consulting and planning, funds management, merchant banking, stockbroking and treasury.
Because of the comprehensive nature of the course, graduates will be particularly well qualified in highly sought after specialised areas such as auditing, budget analysis, portfolio management, investment analysis, mergers and acquisitions, risk analysis and taxation strategy.
Some good colleges are:
Indian Institute for Finance and Management
Indian School of Business & Finance
Ganga Kaveri Group of Institutions
Shankar Narayan College of Arts and Commerce
St. Xavier's College, Jaipur
Amity University
Christ College
Follow this link for colleges: http://www.indiaeducation.net/top-colleges/commerce/