The JPO (Japan Patent Office) and the DPIIT (Department for Promotion of Industry and Internal Trade) announced that the PPH (Patent Prosecution Highway) pilot program between Japan and India will come into force probably from December 5, 2019.
The Japan Patent Office and the Indian Patent Office respectively accepts 100 requests for the PPH per year at the maximum. The upper limit of the request for each applicant has not yet been decided.
Update on November 30, 2020:
As you may know, one of the requirements for using the patent prosecution highway (PPH) in India based on a corresponding Japanese patent application is that examiner has not yet been assigned to the Indian application. However, it was not possible for the applicant to check in advance if the examiner has already been assigned or not, and accordingly, some of the PPH requests were rejected at the DPIIT.
Under the circumstances, the DPIIT database was recently improved and now the applicant can confirm the status of the application in advance here: https://ipindiaservices.gov.in/publicsearch