Hello,
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Look, first point is you can't be a CBI officer with just 10th passed, you need to have atleast a bachelor's degree with 50% and age must be in-between 20 to 27 year's, relaxations will be according to category.
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So, if you are recently 10th passed, go for intermediate and graduation and then go for competitive examination, your age will be managed will relaxations.
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But, If you are 10th passed long ago and if your age is above 24, then sorry but you can't get into CBI, you should go for another selection for job.

If you want to join CBI first you will have to pass class 12th examination and then graduation The reafter you have to appear in the SSC combined graduate level exam where you can join as a post of sub inspector in CBI.

Check the below mentioned link, this might help you in finding your answer more better

https://competition.careers360.com/articles/ssc-cgl-eligibility-criteria