The following persons came to India at one time or another: I. Fa-Hien II. I-Tsing III. Megasthenese IV. Hieun-Tsang The correct chronological sequence of their visits is:

1. The question asks for the correct chronological sequence of the visits of four foreign travellers to India. 2. III. Megasthenese: Greek ambassador to the court of Chandragupta Maurya (c. 302-298 BC). 3. I. Fa-Hien (Faxian): Chinese Buddhist monk who visited India during the reign of Chandragupta II Vikramaditya (c. 399-414 AD). 4. IV. Hieun-Tsang (Xuanzang): Chinese Buddhist monk and scholar who visited India during the reign of Harshavardhana (c. 630-645 AD). 5. II. I-Tsing (Yijing): Chinese Buddhist monk who visited India after Hieun-Tsang (c. 671-695 AD). 6. Therefore, the correct chronological order is Megasthenese (III), Fa-Hien (I), Hieun-Tsang (IV), I-Tsing (II).