Army of Navab
7,000 infantry
5,000 cavalry of Siraj ud-Daulah
35,000 infantry
15,000 cavalry of Mir Jafar
53 field pieces (mostly 32, 24 and 18-pounders)
50 French artillerymen (6 field pieces)
Army of British (Robert Clive)
750 European soldiers
100 Topasses
2,100 Indian sepoys
100 gunners
8 cannon (six 6-pounders and 2 howitzers)
Yet British won the war lead by Robert Clive and following was the reason
1. Siraj ud-Daulah did not bring the tarpaulin sheet to cover the gun powder and before the war it rained. So canon of Navab was ineffective where British canon was saved by the tarpaulin sheet.
2. Betrayal by Mir Jafar Ali Khan, Yar Lutuf Khan and Rai Durlabh (defector).
Impact of the war on history of India and Europe
Imagine if Navad would have won the war then we would have been ruled by the freaking French. And so would have been the whole of Europe. The French would have been kings and British would not have had a chance, as their army would have been annihilated at Plassey. Driven out of India, French would have had a free hand. So in everything that happened in India after Plassey, just replace the British with the French.
Now come to europe/world - French would have been the Kings of the Europe/world? Because the constant inflow of the booty from India gave them the economic power to do it (as was the case of British)