Complex sentence: India is helping develop the Chabahar port and that would give it access to the oil and gas resources in Iran and the Central Asian states, in this it is competing with the Chinese which is building the Gwadar port, in Pakistani Baluchistan.
Split into simpler sentences: India is helping develop the Chabahar port, which will give it access to the oil and gas resources in Iran and the Central Asian states. In this it is competing with the Chinese, who are building Gwadar Port, in Pakistani Baluchistan.