Being 12 Pass Out you need to give the RRB Railway Recruitment Board Examination for good Category B,C and D jobs in Indian Railways. The Exam is highly competitive as the there are huge number of vacancies and positions to be filled each year and Indian Railways is one of the more exciting organizations and provide good benefits and perks.
Perhaps if you are a Graduate, you can give the UPCE CSE Exam for IRPS ( Indian Railway Personnel Service) or the UPSC ESE Exam for IRSE Engineering Positions, both of which are Category A Positions.
Since you have just passed 12th, follow the link below for more information about IBPS RRB 2021
https://competition.careers360.com/exams/ibps-rrb
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