Lock-in restrictions on promoters' securities impose staged release periods following an initial public offer. Lock-in restricts transfer of specified securities held by promoters. The minimum promoters' contribution, including specified institutional and non-individual public shareholders or entities in the promoter group other than promoters, is locked for three years from the later of commencement of commercial production or allotment in the initial public offer. Promoters' holdings in excess of minimum contribution are staggered: fifty percent locked for two years and the remaining fifty percent locked for one year from allotment in the initial public offer. 'Date of commencement of commercial production' means the last date of the month in which commercial production of the relevant project is expected to commence.