Disclaimer: I'm not your doctor, and further, I'm not any kind of doctor. Talk to one before you make medical decisions. However, I do have scientific and research training, and can assess the quality of the scientific evidence on this question.
There does not appear to be any current evidence for the effectiveness of Tonsilotren in treating any condition. For instance, a google scholar search for "Tonsilotren" returns no scholarly works at all.
At present, there is a clinical trial (mentioned in DVK's comment above) which is exploring the effect of Tonsilotren for the treatment of tonsillitis. However, the description of this study explicitly states that it has no formal hypothesis. Further, the study is not blinded at all (i.e. there is no placebo control for Tonsilotren, and both the patients and the doctors know who is getting it, and who is not). The study is funded by the German Homeopathy Union.
All that said, most or all of the ingredients mentioned (though, as far as I can tell, not in exactly that combination or dosage level) have individually been shown to provide relief of pharyngitis by some studies. Other studies have found that they perform no better than placebo. A 2011 meta-study of these issues here summarizes these contradictory findings, but concludes with the upbeat message that, at least at low dilution levels, at least some homeopathic treatments might do something useful for ENT problems. A related meta-study from 2006 focuses only on ENT treatment with homeopathic medication, and reaches somewhat similar conclusions.
However, both meta-studies note that the current state of science for homeopathic medicine is somewhat lacking, because most homeopathic doctors are not interested in a scientific approach to research, and there is relatively little funding for independent study of the subject (i.e. studies not funded by homeopathic medical suppliers). Consequently, I remain pretty skeptical of this work, although I cannot rule out the possibility that, in these low-dilution doses, these medicines might be helpful for treating pharyngitis. I'd personally summarize the state of evidence as something akin to a cure suggested by rural grandparents. There might be something to it (your grandparents weren't born yesterday, and their past experience says it works), but there's not rigid scientific evidence that it works better than a placebo.
