Step 1: Understand Cochin Port's role.
Cochin Port (Kochi) is one of the busiest ports on India's western coastline, serving as a key gateway for trade in South India and the Indian Ocean region.
Step 2: Identify the dominant cargo.
Approximately 68% of the cargo handled at Cochin Port consists of crude oil and POL (Petroleum, Oil, and Lubricants), highlighting Kerala's importance as a major petroleum transit and processing hub.
Step 3: Eliminate other cargo types.
Timber, fertilizer, and coal are handled at the port but in far smaller proportions compared to crude and POL, which dominate overall tonnage.
\[ \boxed{\text{crude and POL}} \]