TDEE and weight loss

I have some questions to ask for help.

1) There are so many types of TDEE on the web and all of them gives me different results. May I know which website will be more reliable?

2) Is 1200 kcal enough for me when I am a full-time student who rarely have time for daily exercises and usually struck to the chair and use laptop to do my school work for more than 8 hours per day?

Age : 23
Ethnicity : Asian
My height : 155cm
My current weight : 61.5kg
Activity Level : Little or no exercise (student)

Here is the list of foods I am now taking daily when I am at home.

Morning
1) A bowl of cooked oat meal
2) 1 glass of milk

Morning Snack
1) 1 serving of apple

Afternoon
1) Two to three types of boiled/streamed vegetables
2) 1 cup of low fat yogurt

Afternoon Snack
1) 1 serving of apple

Evening
1) 0.3 serving of rice (in a plate)
2) 0.3 serving of Salmon fish (twice a week)
3) 1 serving of stir-fry vegetables
4) 0.3 serving of meat (occasionally)

Supper
1) 1 glass of milk
2) 1 packet of low calories hi-calcium biscuit

Please advice. Thanks!