The condition is, as with all free worldwide shipping on Amazon.com, that you have to purchase over $125 USD for Saver Shipping. As ever, you have to search or find the product that you wish to shop for through AmazonGlobal, otherwise it might be ineligible.
Remember that you may still be eligible to pay import duty, although they will estimate the import fee at checkout and provide customs clearance on your behalf, and it is your responsibility to ensure that the items can be exported to your destination of choice.
Amazon will now ship to 65 countries worldwide.
Amazon Global say:
"With FREE AmazonGlobal Saver Shipping, you receive free shipping to India and Singapore if your order includes at least $125 of qualifying merchandise, excluding the Import Fees Deposit, gift-wrap charges, duties, and taxes. Most products shipped using the AmazonGlobal Program that are sold by Amazon.com are eligible for AmazonGlobal Saver. Items 20 lb. or more, certain oversize items, e-documents, software downloads, music downloads, Kindle devices and accessories, and gift cards don't qualify."