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The records for Burriscarra/Ballintober parish start in 1839 and here is a link to the register from 1839-1880 https://registers.nli.ie/parishes/1048 Roots Ireland is a subscription site and has the Burriscarra records from 1839-1900 with a search process which saves time compared to scanning the parish register. If there is anyone in particular you need to search, let me know.
I could not find exact directions to the cemetery but you can contact St. Mary's church in Carnacon http://www.thecatholicdirectory.com/directory.cfm?fuseaction=display_sit...
You should also visit Ballintubber Abbey which is nearby. http://www.ballintubberabbey.ie/
Here is a link to the 1856 Griffiths Valuation head of household listing for Burriscarra civil parish. http://www.failteromhat.com/griffiths/mayo/burriscarra.htm
Let me know if you have questions.