Section 18, The Public Private Partnership Act, 2014

The PPP Agreement shall indicate its duration based onreasonable return on the private partner's investment or service delivery requirements, and the contracting authority may not agree to extend its duration, except as a result of the following circumstances- (a) delay in completion or interruption of operation due to circumstances beyond the reasonable control of either party; (b) suspension of the PPP Agreement brought about by acts of the contracting authority or other public authority; (c) increase in costs arising from requirements of the contracting authority not originally foreseen in the PPP Agreement, if the private partner would not be able to recover such costs without such extension; (d) on agreement with the private partner, for reasons of national or public interest, as justified in the record to be kept by the contracting authority; or (e) as otherwise provided in the PPP Agreement.