The client area lists the two nameserver hostnames for the plan. Enter those at the registrar. Registration done on this site can apply them during the order. Propagation can take up to 48 hours.
Sign in to the client area and keep the order reference nearby. Prices and windows on thedatadynamo.site stay in Indian rupees, with a 7-day cancellation on new hosting orders and no fee return on a domain once it is referenced.
Write the exact error into a support ticket. For mail and DNS, allow up to 48 hours of cache time before treating the change as failed. For a plan that is too small, use an upgrade and pay the difference rather than opening a second overlapping service.