Now if you are below 16 years old
or if you are above 70 years old
then for this age group panchakarma cannot be done
and if you are a women and if you in 
your menstruating cycle days
on these days panchakarma cannot be done 
and for a pregnant women too panchakarma cannot be done
another thing with the emotional aspect
if you have a weak body and weak mind, then
Panchakarma cannot be done
Another thing if you have under weight
or if you have diseases of under nutrition
like Anorexia Bulimia
then Panchakarma cannot be done because
it has to let the toxins out
so if you have to let things out
if you have low weight then
it is a contra indication.
so these are some of the brief aspects 
where Panchakarma cannot be done.