Dear Jeyaseelan.A,
Travel reimursement for Candidates is usually aligned to the post for which he/she is going to be interviewed. For example if you are interviewing a candidate for the post of Manager, then he will be entitled to reimbursement of Travelling Expenditure that a Manager in your Company gets.
As for joining, he is an employee hence your Travel Policy will be applicable and usually a separate provision is kept for Joining which is at par with the Transfer Policy.
Regards,
SC