Tea alone will not make you lose weight.
Weight loss is simply a result of burning more calories (through activity) than you consume through food and drink.
If you consume high calorie food and drinks, no tea will help.
Having said that, tea could be a good substitute for sugar laden sodas, juices or other drinks, lowering your overall calorie intake.
Any tea without milk or sugar should work equally well in practice. Adding milk, sugar, honey etc will increase the calories.
Technically a high caffeine tea should help slightly more by increasing your metabolism, but the difference is barely noticeable.