We have some idea, In 1787 CE, when Hindustan/India was under Maharaja Mahadji Shinde we have Catherine the Great's discussion with Poet Derzhavin. She stated she would not let herself die until she established friendly trade relationship with India under the Maratha Empire.
Catherine the Great's tone in reference to her ambitions related to India becomes far more aggressive after demise of Maharaja Mahadji Shinde. With Colonialist invasions peaking, she hoped that by opening a land-route to India after subduing Iran, she could get in on the action.