Letter written on 7 Sep 1969
Osho wrote many letters to Ma Kusum Bharti and her husband Kapil, then of Ludhiana. Most were addressed to Kusum, but always mentioning Kapil too. All but a few were published in Prem Ke Swar (प्रेम के स्वर). The wiki has images of all but one of those published in PKS, plus a few more.
This letter is dated 7th September 1969, and is one of the few not published in Prem Ke Swar (प्रेम के स्वर). The letterhead is a typical one of those days, showing a simple all-lower-case "acharya rajneesh" at "kamala nehru nagar" in "jabalapur (m. p.)", with his 4-digit phone number and a two-colour Jeevan Jagriti Kendra logo.
See also Letters to Kusum and Kapil