Hii aspirant..

The official website says  -

As per the notice, the DoPT is considering amending the Central Secretariat Service Assistants' Grade (Direct Recruitment Competitive Examination) Regulations, 2010 to increase the upper age limit for direct recruitment of Assistants from the present 27 years to 30 years. In addition, it is also considering removing the restrictions on the number of attempts in the competitive examination for the direct recruitment of candidates to this Grade.


Thus there are no restriction for number of attempts although there is a age limit accordingly.

Hope it helps. 

Best of luck.