IGST on Import (Free supply)

Yes you can avail ITC for the same , but are U supplying those spare parts free to your customer ,.. if Yes then As per section 17(5) ITC has to be reversed

SCHEDULE I ACTIVITIES TO BE TREATED AS SUPPLY EVEN IF MADE WITHOUT CONSIDERATION

2. Supply of goods or services or both between related persons or between distinct persons as specified in Section 25, when made in the course or furtherance of business: Provided that gifts not exceeding fifty thousand rupees in value in a financial year by an employer to an employee shall not be treated as supply of goods or services or both.