RRB PO vs railway technician signal

My preference will be the RRB job.
The payment and career prospectus are better than in railways.
Railway job is also good and you will have chances to get promoted to the next level.
Railway job is more on the technical side. Field job.
RRB job is more of desk work. Not a technical job.
A person who wants to continue the service in the technical field should continue in railways. But candidates who wanted to be stationary and who never want field job can go for bank job. This is the choice of the individual.
If I were you I will go for RRB PO

Before deciding the two, you should see the pros and cons of the two jobs which I am illustrating for your sake - 1) Banking jobs are mainly desk type jobs requiring your full attention in the job assigned to you. It carries financial risks as well if you are placed in such groups.
2) You would have better chances to meet different clients and this would provide you a scope for the better communication.
3) You would come across several oppurtunities to pass departmental examinations and passing the same would enhance your promotional prospects.
4) Taking up an MBA course through the distance mode such as Karnataka Open University, Manipal Distance Education or from IGNOU would enhance your knowledge in the areas of finance helping you faster growth in terms of promotion.
Now talking about the Railway Jobs, it is definitely technical in nature but the drawback is that you have to carry out same nature of job for years and even promotions are effected late. You may be transferred from one place to other depending upon the requirements of Railways causing you some inconvenience.
Hence comparing the two, RRB jobs seem to be best suited.
However, you should see your own area of interest.

You are a lucky person that you are having such an options in your hand to select a job from these two opportunities. There are many considerations for selecting a job but the primarily what matters is the interest of a person and the salary in the particular job. So, I would suggest to introspect yourself for the type of job you are interested in. Would you be more comfortable in the technical job and enjoy it or you would like a white collar job sitting monotonously on a desk and yearning for some break in between. A person can be happy in working in a line which he likes and that is sometimes a major reason in our life to select a career line. Another aspect is the future prospectus. In the banking sector if you qualify in the departmental exams then you can rise to higher posts and many people have gone to the top positions very quickly. In the Railways promotions would not be so fast as it is a big department and many people would be in fray for that.

Apart from above in the field job in the Railways, you would have a change of surroundings and opportunity to go to different places and you would remain active in your life. If you like that type of life then you can consider the Railway job itself. Railway is poised for a big modernisation and the employees would have opportunity to grow as well as work with computerised equipments so from that angle the future working atmosphere in Railways would be better in our country. These are some considerations that you have to visualise at this juncture and take a conscious decision in this matter.