By Neha Arora and Sumit Khanna NEW DELHI (Reuters) -India’s official COVID-19 death toll crossed 500,000 on Friday, a level some data analysts said was breached last year but was obscured by inaccurate surveys and unaccounted dead in the hinterlands, where millions remain vulnerable to the disease. The country, which has the fourth-highest tally of deaths globally, recorded 400,000 deaths by July 2021 after the devastating outbreak from the Delta variant of the coronavirus, according to official data. Some believe the figures were much higher. “Our study published in the journal Science estima…