From an email dated 10/25/15
Re: Why Krishna appeared in India:
Srila Prabhupada explains in a purport - "It is not a fact that the Lord appears only on Indian soil. He can manifest Himself anywhere and everywhere, and whenever He desires to appear.”
If you read the full verse and purport I think you will understand:
yadā yadā hi dharmasya
glānir bhavati bhārata
tadātmānaṁ sṛjāmy aham
Word for word:
yadā yadā — whenever and wherever; hi — certainly; dharmasya — of religion; glāniḥ — discrepancies; bhavati — become manifested; bhārata — O descendant of Bharata; abhyutthānam — predominance; adharmasya — of irreligion; tadā — at that time; ātmānam — self; sṛjāmi — manifest; aham — I.
Whenever and wherever there is a decline in religious practice, O descendant of Bharata, and a predominant rise of irreligion – at that time I descend Myself.
The word sṛjāmi is signiﬁcant herein. Sṛjāmi cannot be used in the sense of creation, because, according to the previous verse, there is no creation of the Lord’s form or body, since all of the forms are eternally existent. Therefore, sṛjāmi means that the Lord manifests Himself as He is. Although the Lord appears on schedule, namely at the end of the Dvāpara-yuga of the twenty-eighth millennium of the seventh Manu in one day of Brahmā, He has no obligation to adhere to such rules and regulations, because He is completely free to act in many ways at His will. He therefore appears by His own will whenever there is a predominance of irreligiosity and a disappearance of true religion. Principles of religion are laid down in the Vedas, and any discrepancy in the matter of properly executing the rules of the Vedas makes one irreligious. In the Bhāgavatam it is stated that such principles are the laws of the Lord. Only the Lord can manufacture a system of religion. The Vedas are also accepted as originally spoken by the Lord Himself to Brahmā, from within his heart.