Wonder what China’s hegemony is all about?..
China’s plan:
Beijing is planning to establish its economic presence in Iran. For the same, China and Tehran drafted the security and economic partnership.Chinese investments will be in banking, Ports, telecom,railways, etc. China’s master plan to establish their activity in Iran and slowly creep into west Asian Region is well targeted and executed.
On the other hand , U.S under Trump’s admin had issued sanctions(restrictions) against Iran and mandated other countries not to have trade with Iran. But the current move by China adds on a contradictory note. In return, Iran being one of the largest producers of oil proposes to supply oil to China at discounted price.
China not only planning for investments in Iran soil, but also for capturing the military presence in the region. By this way, China can also expand its Belt and Roads initiative(Belt and Road Initiative ) in the region. Yes , as we all quite aware- China is showing up its hegemonic sample in whatever way possible. The earlier show of US pulling out of Joint Comprehensive plan of action(Iran Nuclear deal) was not a step in the right direction by the US. This move created rift in US- Iran relationship. The void is well planned and being filled by China.
Impact on India:
Earlier, India listening to US restrictions, had reduced its oil imports from Iran. But now, Iran got a new customer for its oil . China , being a country which imports 75% of its oil needs can get benefited from the discount given by Iran. Anyhow, India started to enhance its imports from Saudi Arabia. But the investments by India at Chabahar port should not be impacted by Chinese activities. Hence, India needs to sustain its balance with Iran and at the same time should not disappoint US restrictions. 
China’s attitude is well noted and soon it may expand its presence in most regions of the globe . Hence the nations need to be careful and should take a calculated move in the global diplomacy. China’s hegemony can be well countered with united efforts at the regional and global level.
Have a good read about India-China