Did prince Rupert have any sons?

Yes he did, albeit illegitimately! Dudley Rupert Bard of Francesca Bard, Lady Bellamont in 1666. Educated at Eton, entering Coldstream Guards and his father's profession. Unfortunately did not have his father's charmed life and was killed in 1688 fighting the Turks at Buda. Reputedly of a fair complexion with little resemblance to his father physically or tempermentally.