Given:
Let's analyze the information:
Let's assume Arun bid Hi alone in the second and sixth rounds:
Now, let's analyze Bankim and Dipak's scores after the sixth round:
Considering this, Bankim and Dipak both bid Hi in the first round and Lo in the second and fourth rounds.
Now, let's find the round where all four players made identical bids:
So, all four players made identical bids in 2 rounds.
Therefore, the answer is 2 rounds.