1. A method for generating test strategy for a software application, the method comprising: receiving, by a test strategy generation system, a plurality of parameters from internal data sources and external data sources; determining, by the test strategy generation system, one or more behavioural patterns for the plurality of parameters of the external data sources; calculating, by the test strategy generation system, a score for the plurality of parameters of the external data sources and the internal data sources based on the one or more behavioural patterns and a weightage; comparing, by the test strategy generation system, an aggregate score with corresponding threshold weightage value for the plurality of parameters, wherein the aggregate score is calculated based on the score for the plurality of parameters; generating, by the test strategy generation system, test strategy parameters based on the comparison; and filtering, by the test strategy generation system, a set of test cases from a plurality of test cases for the plurality of parameters based on the test strategy parameters.