This looks like his birth with a mistranscribed surname. This certificate will give you the names of his parents. The marriage certificates will name his father.
https://www.gro.gov.uk/gro/content/certificates/Births Jun 1842
CLACKITT Robert George Maidstone 5/299
I can't find him on the 1851 census but there is a George
CLACKETT aged 7, pauper, son of a soldier in the Union Workhouse Isle of Thanet. HO107/1629/132/17
Marriages Jun 1869
CLACKETT Robert George Maidstone 2a/837
HEWITT Rose Alice Maidstone 2a/837
Births Jun 1870
CLACKETT William Charles Maidstone 2a/588
Marriages Mar 1888
CLACKETT Robert George Maidstone 2a/811
WARNES Selva Maidstone 2a/811
Cando
