It mainly depends on the promptness of the local discoms in granting persmissions, the cooperation of your vendor and the response of the National Rooftop Portal in processing the response. In case there is no meter load enchancement need, the whole process usually takes 30-60 days in most states. In states like Gujarat the whole process often gets done within one month. In case a person wants to increase the sanctioned capacity, this process alone takes one extra month besides normal rooftop solar installation time. But the meter load enchacement request is often made before applying for rooftop solar.