Nisargadatta advised the seekers to dwell on the thought of "I am" as the practice for achieving realization. Do I need to accurately understand what "I am" means in order to practice this correctly? It is translated from Hindu to English. Is possible the exact meaning get lost during the translation?
No, you must know what "I Am" means to you. Not what it meant to anyone else including Maharaj or any of the hundred neo advaita gurus out there.
What is I Am to you? Locate it, Stay there. This is your central feeling that you exist. Read Hunting the I. Forget "I Am That." Read only the meditation manual "Nisragadatta Gita."
This is a matter of getting away from the mind with all of its speculations, philosophies and meanings, and just sense "I Am," I live, I exist. Isolate that feeling then join it, become one with it.
All Advaita texts from all the teachers say the same thing. Abide in the sense of I, or I Am.
It is so simple. Do not make it complicated with speculations about inaccurate translations.