Background: Sexual and gender minorities (SGM) using smartphones to seek partners in India are vulnerable to HIV acquisition as they are outside of the government’s physical-hotspot-focused interventions. As an underreached and under-researched population, little is known about the reach of HIV-related public health messaging and services for this population. We investigated the coverage of contemporary HIV prevention strategies like daily Pre-exposure Prophylaxis (PrEP) and perceived accuracy of Undetectable=Untransmittable (U=U) among to identify the gaps and lost opportunities in the HIV prevention space for online SGMs in India. Methods: We conducted online cross-sectional study (March-April 2022) of Grindr users across 33 states and union territories in India, including individuals =18 years who reported sex with men. Cisgender women were excluded. Associations with perceived U=U accuracy and PrEP use were estimated using adjusted prevalence odds ratios (aPORs) with 95% confidence intervals (95%CI). Results: The median age of 3126 eligible participants who completed the survey was 28 years. 70.6 % (N=2206) identified to be from urban areas. 82.5% (N=2581) self-identified as male, rest identifying as transwomen, hijra, Kinner and other identities. The self-reported HIV prevalence in the sample was 3.1% (N=97). 7% (N=219) of participants reported ever using PrEP, which was associated with higher income (>INR 62,000 aPOR 1.94 [95%CI 1.19, 3.14]), selecting English language for survey (aPOR 1.70 [95%CI 1.21, 2.40]), single relationship status (aPOR2.35 [95%CI 1.45, 4.04]), and use of party drugs (aPOR2.57 [95% CI 1.65, 3.93]). After being provided with the correct definition of U=U, 25% (N=782) perceived it as completely accurate, which was associated with knowing their HIV status (HIV Negative aPOR 1.37 [95%CI 1.1, 1.71], HIV Positive aPOR 3.39 [95%CI 2.11, 5.46]), having awareness of PrEP (aPOR1.58 [95%CI 1.29,1.92]) or have used PrEP (aPOR1.56 [95%CI 1.15, 2.12]) along with use of party drugs (aPOR1.51 [95%CI 1.0 2.10]) and attending LGBTQIA+ events (aPOR1.38 [95%CI 1.1, 1.73]). Conclusions: With low perceived accuracy around U=U and low PrEP use, SGM using smartphones in India are missed by contemporary novel HIV prevention strategies. We recommend incorporating PrEP and U=U in programmatic interventions and adopting innovative digital strategies that could reduce stigma and promote HIV prevention.