Priests Gaga Bhatta and Nischal Puri had approached for Shivaji Maharaj’s coronation. Gaga Bhatta, was a follower of the Vedic system of Hindu theology and the patron of Brahmans belonging to that school, while Nishchal was the champion of the Tantrik school, and the two differed greatly. Gaga Bhatta was selected as a director of Shivaji’s coronation rites, so, the coronation was performed according to the Vedic ritual and only Vedic Brahman benefited from the golden shower of the Rajah’s bounty at the ceremony,-while the Tantrik mendicants sent by Nishchal to share the royal alms were driven away with abuse.
After the Shivaji Maharaj’s coronation was over on 6th June 1674, Jija Bai died on 18th June, in the fullness of years and happiness. According to Nischal Puri, Gaga Bhatta made a wrong astronomical calculation and thus performed the coronation on a day when the malignant stars were in the ascendant. He made, the king worship only the Vedic gods and scornfully ignored the spirits and goblins adored in the Tantra. A number of the most unaccountable mishaps thus took place the queen-consort Kashi Bai, the Queen-mother Jija Bai, the commander-in-chief Pratap Rao, all died within a short space of time. Immediately after the king had left the coronation-hall, a piece of timber hit Gaga Bhatta’s nose,-unquestionably an act of divine retribution for his having made Shivaji believe that Nishchal was not “worthy of being bowed to”-and, of getting a half share of the purse of 7,000 gold pieces presented by the king to Gaga! This favoured high priest’s sin had infected his assistant Balam Bhatta, on whose head the wooden lotus of a pillar in the hall tumbled down.
This unearthly evidence conclusively proved that the Vedic gods could not protect their votaries so much as the Tantrik devils could hurt. Shivaji maharaj, like a practical man that he was, decided to woo both of these supernatural hosts. Therefore he requested Nischal Puri to conduct a Tantrik coronation for him just after 3 months of his first coronation. This was done on 24th September. (the date is mentioned as 4th October in some articles.)
Reference:
http://shivchhatrapati.com/biography/shivaji_coronation4.php#
http://www.ssmrae.com/admin/images/28ba4b40e997cbddcb1d542cb6c5c765.pdf
This Day in History 
Some people recently started advocating that 2
nd coronation of Shri Shivaji Maharaja the Great is carried out as per the Buddhist philosophy as he was denied first coronation as he was not considered as Brahmin a super caste for being King as per Hindu philosophy,and since the Buddhism was still exists,he performed the ceremony according to Buddhism. Can you throw more lights on this propaganda.
Dear Bagul, Thank you for the comment. The blog ‘This day in history’ is a compilation of events from various sources. I’ve mentioned the sources at the end of each post.