Solution:
The Nationalist Congress Party was formed as a split-away faction of the Indian National Congress in 1999 due to internal party conflicts. The party went on to enjoy popular support in the state of Maharashtra, and it became its stronghold. The party bases its politics on the idea of Gandhian secularism, among others. However, this doesn't explain its formation. These are just the features of the party.Thus, both the Assertion and Reason are True. But the Reason is not the correct explanation for the Assertion.