How to file application in high court to make party in ongoing case

Dear sir,we are in position of the land for the last 50 years which is granted to third party but RTC and katha was in the name of my grand father and paying tax from 1975 to 1997 as unauthorised cultivators & aplied form 50 53 for grant of land.in 1998 RTC and katha suddenly changed to grantees name & thahsiladr issued notice to us.after the case is going on in different courts.in the meantime grantee sold the land to third party in 2005 when there is a case pending before KAT court.after the so called purchasers filed a eviction suit in civil court in 2014. In this time I found a document in thaluk office that mentioned, the grant land which is sold in 2005 by grantee is canceled by divisional commissioner in 1979.I surprised and Finaly I got attested copy of grant cancelation order and filed in civil court in 2016. After that opposite parties filed wp in high court for quash the divisional commissioner order after 37 years without making us parties.how to approach high impleding