How many times is Gabriel is mentioned in the bible?

Answer 1

Four times total. This is from the English Standard Version:

Daniel 08:16 And I heard a man's voice between [the banks of] the Ulai, which called, and said, Gabriel, make this man to understand the vision.

Daniel 09:21 yea, while I was speaking in prayer, the man Gabriel, whom I had seen in the vision at the beginning, being caused to fly swiftly, touched me about the time of the evening oblation.

Luke 01:19 And the angel answering said unto him, I am Gabriel, that stand in the presence of God; and I was sent to speak unto thee, and to bring thee these good tidings.

Luke 01:26 Now in the sixth month the angel Gabriel was sent from God unto a city of Galilee, named Nazareth,

Answer 2

Only one appears to Daniel and Mary, the mother of Jesus.