Patthuvardhan, who won the Gurjar region, was the ruler of which dynasty?

"Patthuvardhan" refers to Prabhakaravardhana, the ruler of Thanesar and father of Harshavardhana. He belonged to the Vardhana dynasty (also called the Pushyabhuti dynasty). Banabhatta's Harshacharita praises his many conquests, famously describing him as "a troubler of the sleep of the Gurjaras" - i.e. he subdued the Gurjara power on the north-west, along with victories over the Hunas, the king of Sindhu, the lord of Gandhara and the Latas. Hence the correct dynasty is the Vardhana dynasty.