Yes, his brothers were:
He was the younger brother of King Louis XVI.
Louis XVI (the sixteenth / seize)
Louis XVI was King of France at the time of the Revolution. He and his wife Marie Antoinette were beheaded by guillotine at the start of the reign of terror during the revolution.
No, Louis xvi is not single.
Louis XV was the grandfather of Louis XVI
She married Louis-Antoine, duc d'Angoulême, her cousin. He was the son of Count D'Artois, brother of Louis XVI.
Louis XVI never had a grandchild.
Louis XVI of France.
Louis XVI, who was beheaded along with his son, the [presumptive] Louis XVII. When the monarchy was restored, Louis XVIII became king.
louis xvi along with his wife was guillotined
The King was Louis XVI.
Trial of Louis XVI happened in 1792.