Gap between Trim and Textframe

@balaji –

Sort of a "geometric solution", especially if your text frame is rotated and/or skewed:
use a helper rectangle the size and position of your desired trim box, combine the text frame with the helper rectangle to a group and check if the geometric bounds of the group are different to the helper rectangle.

WARNING:

I have to point out that this solution is pure theory, because you cannot be sure that part of single characters or applied effects to the text frame like drop shadows will not exceed the helper rectangle. Or imagine the case where a table sticks out of the geometric bounds of the text frame and violates the trim box.

For that advanced cases you need a rendered pixel representation (e.g. of an exported pdf) and you have to do cross-scripting InDesign to PhotoShop with bridgeTalk to check if there are any pixels violating the bounds of your trim box. Not an easy task.

Uwe