Here is the civil marriage record for John's parents Richard McNicholas and Margaret Deacy. The names of their fathers are shown on the record. The McNicholas family was from Lagcurragh townland in Kilconduff civil parish and the Deacy family was from Rubble.
John's civil birth record see fourth record https://civilrecords.irishgenealogy.ie/churchrecords/images/birth_return...
Other siblings Michael 1867 Richard 1868 (died young?) James 1868 unknown 1869 Bridget 1870 Sarah 1873 Richard 1874 Pat 1877 Mary 1879 Martin 1886
See fifth and sixth records Richard died in late 1911 and Margaret died in 1912
Let me know if you have any questions.