The memorandum mentions the schedule of the event, Revolution Day, at the Martyr's Memorial in Panaji where the chief minister would arrive.
"Arrival of honourable Chief Minister. He will be received by Chief Secretary and Director General of Police," the memorandum states, also listing Mr Parrikar's speech at 9:25 am.
Mr Parrikar, 62, is undergoing treatment for a pancreatic disease at a New York hospital. The former defence minister had been hospitalised thrice before he was taken to the US. While in India, he was admitted to Mumbai's Lilavati Hospital and Goa Medical College.
Although BJP claims he is likely to arrive in Goa later this month, similar assurances made by BJP leaders in the last three months haven't come through.
In his absence, a three-member ministerial committee is running the BJP-led coalition government in Goa.
Mr Parrikar will not return to Goa by June 18, a senior BJP leader told news agency IANS. "We are not aware of his return to Goa. As far as we know, there are some tests which are expected to be conducted later this month. But as far as the party is concerned, he will not be in Goa to attend the June 18 function," said the leader who asked not to be named.
Last week, Goa agriculture minister criticised the Congress for making an issue out of Mr Parrikar's absence in the state, and maintained that the state administration was being run smoothly.
He claimed the Congress was trying to use Mr Parrikar's absence from Goa as an opportunity to revive itself, after failing to come to power in the coastal state following the assembly election last year.