Open Question: How much weight can I lose in one month on this diet?

Breakfast: 300 calories maximum Lunch: 300 calories maximum Dinner: Around 400-600 calories (it depends... I have to eat what is served) Snack: 50 calories So that's a maximum total of 1260 calories. And I exercise for 1-2 hours every day (usually 2) and drink 2 litres of water each day. I apparently have a BMR of 1400, according to online BMR calculators. Thanks. Oh and I don't eat meat,