Without any specific info about the actual source properties, how it was created/ recorded, footgae interpretation and so on this isn't going anwhere. A screenshot would likely also help a lot. And well, not to point out the obvious: If you use an old version like CS5 with a new camera that may e.g. use fancy stuff like custom view/ crop regions, you're pretty much out of luck and the file may require external conversion.
We record vibration testing, and i need to put a time stamp using Affter effects time code in the video. We're not doing anything fancy. We are using a Canon XA-11, which we just bought. Previously we used a Canon XL-2 which used mini-dv tapes and used Premeire to capture the video. The new camera uses sd cards and records to MTS file format.
The attached file shows approximately the same frame but the After effects frame appears cropped.
There's nothing cropped. Since you are at 100% zoom the layer content is simply maxing out the comp viewer wherea in your Premiere screenie you are at 50%. You may want to read the help on basics like zooming and al lthat good stuff.