Maintenance mean number of calories your body requires, no more no less. Eating maintenance you theoretically wouldn't gain or lose weight.
Basic nutritional macros:
For protein, lifters in general will say 1 gram per pound of bodyweight minimum. 90kg=200lb so 200 grams is your minimum.
Fats at around 20% of your target caloric intake. Try to stick to good fats (as in eggs, olive oil, etc).
The rest as carbohyrdrates. Its best to avoid simple carbs and eat complex carbs.
Remember that 1g of protein has 4 calories, 1g carbs is 4 cals, and 1g of fat is 9 cals.