There are a lot more manuscripts in the university collection. An 1839 catalogue of the manuscripts can be read here http://idb.ub.uni-tuebingen.de/diglit/MhIII118-1/0001?sid=f05289236bd266a5da... 870 is the figure given on http://idb.ub.uni-tuebingen.de/digitue/tue/Ma_I_Indische_Handschriften
best wishes Shyamal