Find out the correct chronological sequence of the following persons’ visit to India at one time or another: (1) Fa-hien (2) I-Tsing (yijing) (3) Megasthanese (4) Hiuen-Tsang?

The correct chronological sequence is 3, 1, 4, 2.

To determine the correct order, let us look at the approximate timelines of each person's visit to India:

1. Megasthenes (3): He was an ancient Greek historian, diplomat, and Indian ethnographer in the Hellenistic period. He visited India as an ambassador of Seleucus I Nicator to the court of Chandragupta Maurya (founder of the Mauryan Empire) around 302 BCE – 288 BCE.
2. Fa-hien (Faxian) (1): He was a Chinese Buddhist monk who traveled to India on foot to obtain Buddhist texts during the reign of Chandragupta II (Chandragupta Vikramaditya) of the Gupta Empire, around 399 CE – 412 CE.
3. Hiuen-Tsang (Xuanzang) (4): He was a famous Chinese Buddhist traveler and scholar who visited India during the reign of King Harsha (Harshavardhana) around 630 CE – 645 CE.
4. I-Tsing (Yijing) (2): He was another prominent Chinese Buddhist traveler who came to India to study at Nalanda University and collect Buddhist texts, visiting around 671 CE – 695 CE.

Arranging these visitors in chronological order based on their time of visit:
Megasthenes (3) ⇒ Fa-hien (1) ⇒ Hiuen-Tsang (4) ⇒ I-Tsing (2)

Hence, the correct sequence is 3, 1, 4, 2.