hi sameha
well i will suggest you to write this exam in march or jan or november, good months, rest is upto you.
regarding books: mainly just focus on anatomy, kisner and colby, o'sullivan npte book, few detailed chapters from o' sullivan red book, and ofcourse the electrotherapy which ever you studied, well i am from brampton, ontario where are you from, i alredy have a study group you are welcome to join this group anytime. or else we can share notes with eachother andso on
good luck