Your choice is good and zeal to become a police official is appreciated. After finishing SSC, you should do 10+2 equivalent in any govt. recognized institution, regardless of either maths or biology or any steam. But I suggest you to take maths stream, as it would be easy and wide scope in the future. Age limit is 18 to 21 for male and 18 to 25 for female candidates. It is necessary for a male candidate to possess driving licence, experienced.

During preparation you are obviously jobless seeking for atleast a job either it is desired or not. But after clearing CGL you become a tax paying citizen of India. It is really a proud thing.During jobless nobody cares about you that what and which type of struggles you are facing. Everyone tries to make fun of your condition. Everyone thinks you are just wasting you parents money by doing preparation. But after getting job and a uniform job, everyone respects you. Everyone wants to tell others that you are his friend or relative. Everyone praises your efforts now.Being jobless you have to kill many desires because of lack of money or you don't want to waste your parents money. But after getting a job, you get salary for spending on what you like, no one there is for stopping you.Being jobless you don't maintain your personality, you don't care about your behavior, thinking etc. But after getting job and a uniform job, you have to maintain your personality, way of talking, thinking etc.