Palitana’s Nagara-style Jain temples were constructed beginning in the 11th century CE. The traditional accounts credit the early stone temples to the 11th–12th centuries (with Kumarpal of the Solanki dynasty noted as a key patron), and the site saw ongoing temple building, repairs, and renovations across the centuries, especially through the 16th century and later. In short: the core Nagara temples date from the 11th–12th centuries, with much of the later expansion and renovation occurring from the 16th century onward. You can read more here