It is definitely possible to make the switch from undergrad EE to grad physics but it requires a little extra work. I also don't think that it is likely to get into top rated physics programs, there are just too many competitive applications from students who already have a full physics bachelors degree. Most graduate schools specify a physics degree as a program requirement, but some are willing to make exceptions. Look for wording such as "physics or closely related area" and ask departments about your specific situation. Some will encourage you to apply, others might even be willing to look at the classes that you've taken to assess your preparation for graduate physics work.
I applied to physics graduate programs as an engineering major (BSE degree with electrical concentration) and a physics minor, which I'm sure helped. Each department that replied to my questions about applying with an engineering major said basically the same thing: the important consideration was what classes I had taken, and how well I did in them. They were especially interested in knowing what physics classes I had taken. Some programs are flexible enough to work with the student to arrange a course schedule that fills in any gaps in their physics education, but that takes time and costs the physics department money. But it is done, there are occasionally graduate students taking undergraduate physics courses. I expect to be taking some this fall. I was accepted into 2 programs, and made it to #1 on the waitlist of another before withdrawing my application. I also know of several other international students (I think that they were Indian also, actually) that were planning on switching from EE to physics. I think most of them congregate over at the yahoo physics gre group. Search this site also and you'll find others.
As for taking the Physics GRE, you'll have to assess your level of preparation. I would recommend a lot of studying, because a good physics GRE score can help demonstrate that you have a good grasp of basic physics. Since you're graduating this year, I assume that you're planning on applying for fall of 2009. I recommend starting now for the fall 2008 PGRE test. Try and spend some time each day, as consistent studying will help improve your speed and retention. Start with studying the fundamentals, and then take one of the practice tests in test like conditions to see where your holes are, and concentrate studying that material.
It can be done, but be prepared to put in some extra work, good luck,