Dear Sunil,

There is not a particular type of restriction in any SSC exam if you have tattoo on your body, in there medical standards they haven't mentioned anything regarding to tattoo, so a tattoo will not stop your way too clearing the medical part of any SSC exam.

Still it will be more better if your tattoo is based on some religious type or background, try to have it on the inner part of you body most likely elbow or hand. And it should be 1/4 of the total size of actual tattoo for safe side, but in SSC you will not face any type of problem because of tattoo.

Best of Luck!!!