Kaalsarp Dosh is a planetary alignment in a person's horoscope that is believed to cause difficulties and challenges in life. The belief is that when all the planets are situated between Rahu (the north lunar node) and Ketu (the south lunar node), it creates a Kaalsarp Dosh. There are various rituals and puja (prayer) ceremonies that can be performed to mitigate the negative effects of Kaalsarp Dosh in Nashik, you may be able to find a Hindu temple or a pandit (priest) who can perform the Kaalsarp Dosh puja for you. It is always a good idea to consult with a knowledgeable and reputable astrologer before making any decisions about puja or other remedies for astrological issues.