Who was Britains rival for the control of india before 1800s?

Answer 1

France. It ruled over a great part of India's eastern coastal regions and the regions formally allied to France or under its 'considerable influence' at one point - that is, around 1740 / 1750 - covered some 80% of India's territory, by far exceeding British influence in India. France's dream of turning all of India into its colony proved its undoing there. The British cleverly played on local rulers' reluctance to become mere figureheads within a French colony. With their support, the British defeated the French forces in 1757 and drove them back to a few remaining possessions in southern India.

Although it's often thought that British rule covered all of the subcontinent, France managed to hang on to its remaining colonial possessions there until India's independence in 1947. And Britain itself never directly ruled over most of India itself. A very large part of it remained under the rule of local Maharajahs until 1947. The British of course did make sure that their influence was considerable there and especially, that they retained control and dominance in all military matters and organizations.