To generate your kundli you have to provide date of birth, place of birth and accurate time of birth. Please remember the accuracy of Lagna, rasi, nakshatra and planet placements depends upon the time of birth accuracy. Predictions will also go wrong if the time of birth is not correct. But there is a way if you do not know the exact time of birth a blessed astrologer can do a reverse calculation to know about your kundli and there are other occult science which are being practiced since ancient times such as palmistry, Tarot, Psychic readers who can defenitely help.