The correct answer is option 3, Sung Yun.

Option 1, Hiuen Tsang, is incorrect. While Hiuen Tsang is indeed a famous Chinese pilgrim who visited India, he did so in the 7th century, not the early 6th century.

Option 2, Fa-hien, is also incorrect. Fa-hien, another renowned Chinese pilgrim, visited India in the 5th century, not the early 6th century.

Option 4, I-tsing, is also incorrect. I-tsing was a Chinese Buddhist monk who traveled to India in the 7th century, not the early 6th century.

Therefore, the correct answer is option 3, Sung Yun, who was a Chinese monk who visited India in the early 6th century.