I can help
@ps3linux , if you have queries about naadi astrology. Yes it uses palm leaves, in fact I have been couple times to the temple which is somewhat of the heritage point (in modern times) for this astrology....but in my case for more conventional purpose...and also general prayer for good health (its a healing/health focused temple).
I personally don't believe in it (astrology) much and overall I am fairly ignorant of the astrology realm itself in my culture (past knowing of the broad contours and also basic planetary/solar astrology)....but my dad (and mom to some degree) is quite a huge believer and very well versed in it (his big disappointment in me is I never picked up this interest and belief). I would say my genetic disposition in my family for astrology has transmuted inside me to a keen undying interest in
astronomy.
I can pass on questions if you have.... a lot (on finding your fortune through naadi leaf if it exists) is basically based on horoscope information and then stuff like palmistry if I remember correctly.
I am fairly ignorant to how much authenticity of this stuff is done in North India and rest of India at large...I have just heard some astrologers there also know of it and if well-meaning (imo) generally at some point will direct you to TN astrologer core at the temple I speak of (Vaitheeswaran), or some of their direct offshoots....as this is basically where the biggest repository of naadi leaves actually are....which is long drawn out story on its own.
There are a few buddhist astrologers that work a similar way iirc, when I saw a documentary on Tibetan buddhism one time.