Hey Mitali,

Your question is quite open ended since you've used the abbreviation. There are two SSBs, one is Shasastra Seema Bal and one is Staff Selection Board.

For joining Shasastra Seema Bal, Selection Commission (SSC) conducts an examination for the recruitment of Constables and Sub-Inspectors. Staff Selection Commission (SSC) also conduct examination for the recruitment of Constables and Sub-Inspectors. Assistant Commandants are recruited through a Competitive Examination conducted by Union Public Service Commission (UPSC). Assistant Commandants ( Group "A" Gazetted Central Service) are subsequently promoted to the rank of Deputy Commandant, Second-in-Command, Commandant, Deputy Inspector general, Inspector General and Additional Director General and Director General over the years. You should be between 18-23 years, not more or less to apply. You have no limits for attempts.

Whereas for Staff Selection Board, you have age limits as well. Age depends on your academy. For OTA it is 19-25, for IMA it is 19-24, for AFA it is 20-23 and so is for navy. Examinations are conducted twice a year and there are no limits until you cross the age. 

Hope this helps, good luck!

The answer to this is question is no , there are no limits on the number of attempts in ssb , you can go as many times as you are eligible , before you cross the age limit. There are people who are recommended in there 21st attempt. So never loose hope , hustle . As far as the technicality goes make sure you you don't hide your attempts in your PIQ FORM .the authorities are known to take strict action against such acts.