On the Nutrition Facts label, look under “Fats”.
See if it lists the “Polyunsaturated Fats” (PUFA). Omega 3 and Omega 6 are both polyunsaturated fats. Most labels will not list out the amount of Omega 6. Since most foods have higher amounts of Omega 6 compared to Omega 3, I assume the total amount of “Polyunsaturated Fats” is the amount of Omega 6 in that food.