Generative artificial intelligence (GenAI) tools can produce fluent explanations, summaries, images, code, and answers, but fluent output is not necessarily accurate, unbiased, private, or educationally appropriate. For secondary-school students, meaningful literacy therefore extends beyond awareness or frequency of use. It includes functional understanding, purposeful use, critical verification, calibrated trust, recognition of risk, and responsible behaviour. This paper develops an academically grounded protocol for investigating these dimensions among students in Classes IX and X in India. The proposed cross-sectional, multi-site survey uses a mixed-format instrument combining objective knowledge items, self-reported competence, behavioural-frequency measures, and scenario-based verification tasks. The conceptual model treats GenAI literacy as five related constructs: functional AI understanding, applied AI competence, critical evaluation and verification, risk and ethical awareness, and responsible AI behaviour. Access, school context, language, prior instruction, and usage patterns are treated as contextual predictors, while trust is examined as a calibration variable rather than as an uncomplicated indicator of literacy. The protocol specifies a realistic independent-student sampling strategy, pilot testing, translation procedures, content and construct validation, reliability analysis, ethical safeguards for minors, and an analysis plan that accounts for clustering and multiple comparisons. It also supplies participant materials, a complete draft questionnaire, and a variable-coding framework. No empirical findings are reported because primary data have not yet been collected. The study is designed to produce transparent, reproducible evidence about how Indian secondary-school students use GenAI, how they judge its outputs, and what forms of school-based instruction could strengthen safe, critical, and responsible use.