Quetta is the capital of Balochistan province in Pakistan. If you are taking the overland route from Istanbul to New Delhi without going through Afghanistan you will have to pass through Quetta.
Quetta is an excellent base for exploration of Balochistan. Kan Mehtarzai (2224 meters), the highest railway station in Asia, is a two-hour drive away. Loralai, the almond bowl of the country, is 265 km away. Besides, there are numerous other valleys that are fascinating places for explorers.