I had earlier written about the requirement to write to the joint secretary to get permission for travel by private airlines. Please follow the format given here. You can write to one of the following,
Joint Secretary Shri P.N. Sukul firstname.lastname@example.org 24610386
Joint Secretary Shri Alok Sinha email@example.com 24616303
Under Secretary Shri S.K. Chhikara Chhikara.firstname.lastname@example.org 24610372
You can fax the letter to 24640213 or call Sharma at 24632950 ext 2873.
Please add STD code of (011) to all phone numbers above.