Will my high English score in 12th standard help me get a waiver for the English language test requirement?

Yes, it may help but it depends on the universities and programs you are applying to. If a university has a policy to grant English language waivers based on Class 12 English scores, then you may be eligible for a waiver. Waiver eligibility can also depend on your education board (CBSE, ISC, State Board, etc.). Also, not all universities grant waivers, and some still require IELTS, TOEFL, or another accepted English proficiency test.