Authorized dealers can release foreign exchange up to USD 25000 for a business trip to any country other than Nepal and Bhutan. Release of foreign exchange exceeding USD 25000 for a travel abroad (other than Nepal and Bhutan) for business purposes, irrespective of period of stay, requires prior permission from Reserve Bank. Visits in connection with attending of an international conference, seminar, specialized training, study tour, apprentice training, etc., are treated as business visits.
Incidentally, no release of foreign exchange is admissible for any kind of travel to Nepal and Bhutan or for any transaction with persons resident in Nepal and Bhutan.

Business visits sponsored by firms/companies/organizations in India, journalists deputed on short-term assignments abroad by newspapers / journals and self-employed professionals like Solicitors, Chartered Accountants, undertaking visits abroad in connection with their profession.

Letter (in duplicate) from the sponsoring firm/company/ organization [from the applicant in cases of self-employed professionals] indicating name, address, nationality, passport number of the traveler, duration and nature of visit to each country, exchange required and certifying that the expenses are being borne by them.

Resident Indian citizens are eligible under the scheme of Basic Travel Quota(BTQ) to avail of foreign exchange up to U.S.$ 10,000 or its equivalent for undertaking one or more private visits to any country abroad (except Nepal and Bhutan) in any calendar year. Foreign nationals permanently resident in India are also eligible to avail of this quota provided they are not availing of facilities for remittance of their salary, savings etc. abroad.

Passport of the traveler should be verified by the authorized dealer to ensure his eligibility for release of exchange under BTQ.
Passport of the traveler should be endorsed with the amount of exchange sold and notation 'Basic Travel Quota' under proper authentication with stamp and date. A photocopy each of the relevant pages of the traveler's passport where personal particulars are available for example, name, address, date of birth, signature, photograph and number, date, place of issue and validity period of passport, visa for country of visit and the pages where endorsement for BTQ has been made.
In the event of cancellation of the journey and surrender of exchange to the authorized dealer, the endorsement on the passport relating to the exchange sold may be cancelled by the authorized dealer under his stamp and signature with date.

Yes, you will get change back.

Reserve Bank of India Regulations permits tourists/NRIs to freely change foreign currency travelers cheques to Indian Rupees.