Important point is, why your friend is sending money into your account? Doesn't he have his own account in India? For yor friend!? What exactly you mean by this.
Is he a foreign national, in which case also why he is sending money to you, there should be a known purpose.
Unless the purpose and reason for such money is being credited to your account, it's not possible to give clarification.
Your banker must have asked you these questions before crediting the foreign inward remittance into your country. Inform, or may be since the remittance is less than USD 10000 or its equivalent in other currency, as per extant FEDAI rules, bank might have automatically converted and credited to your account.
Please give full and correct details.