What is the problem between nawabs …

The conflict between Bengal Nawabs and the East India Company started when the nawabs refused to grant the company concessions and demanded large tributes for the company's right to trade.The nawabs also denied the the company any right to mint coins and stopped it from extending its fortifications.
The Bengal nawabs accused the company of deceit, and claimed that the company was depriving the Bengal government of huge amounts of revenue and underminig the authority of the nawabs and disrespecting them.
The company also had its grievances against the nawabs. it felt that demands of nawabs were unfair and that their trade could flourish only if the duties if the duties were removed. The company wanted to enlarge its fortification and built forts. All this led to conflicts between the Bengal Nawabs and the compay.