> i want to know whether for loop in vhdl is synthesizable or not???
Yes it is, but it will produce completely different results than a
loop in any software programming language!
> so what it means parallel logic?
In software a loop will be processed one loop after the other, in
hardware ALL of the loops will exist next to each other. And the whole
loop will be executed the very same time!
> dose it creats any problem in design later?
Try it with a short and simple sample code...
Or: show your code...