Dear Sunny,

Railway is a Central government Job before you join any types of job in railway you have to clear entrance exam conducted by railway. There are lots of Entrance test offered by Indian Railways but there having certain criteria so you have to follow this.

Generally practice and more focus on Quantitative Aptitude,Verbal reasoning,General knowledge and current affairs etc...and per week attempt mock test those are freely provided in internet various sites. or join Coaching classes for clearing you doubt and gain extra knowledge.

Thanks