Ref. No. 1104/42-319
In the name of Allah the most Gracious the most Merciful
The answer to your question is as follows:
As we know Coca cola, Thumps-Up etc contain no impure and Haram substances and there are no other reasons to label these drinks with haram, hence it is lawful to drink. However, some doctors consider these drinks injurious to health hence suggest avoiding them.
And Allah knows best
Darul Uloom Waqf Deoband