you have to provide documentary proof of the source of the funds sought to be remitted and C.A. Certificate in Form 15CA and 15CB.
The formats and submission details are available at the Tax Information Network website of the Income Tax Department, at https://www.tin-nsdl.com
Form 15 CB needs to be certified by a Chartered Accountant. To download the form please visit the following link: (https://www.tin-nsdl.com/downloads/Form15CB.PDF) On the basis of this certificate, Form 15 CA has to be filled in online at the following link: (https://onlineservices.tin.nsdl.com/TIN/JSP/tds/Form15CAHome.jsp). The printout generated from this site has to then be signed by the remitter and submitted along with Form 15CB at the branch from where the remittance is being made. The detailed process of filling up the form is also available at the above mentioned site. The filled up form then needs to be produced along with the 15 CB to the branch.