What if the Russian Empire possessed an Indian port like Goa during the Russo-Japanese War?
Short answerIt would greatly improve Russian resupply and repair before Tsushima, provided the base survived British opposition and held sufficient stores.
NotesThe Second Pacific Squadron badly needed a secure place to restore machinery and replenish stores during its voyage. A Russian enclave near India could shorten supply lines and give the fleet a pause before Tsushima. Britain would probably have neutralized or destabilized such a base because it threatened the approaches to India. If it endured, its value would depend on communications and a stockpile large enough to rebuild the fleet's fighting condition.