As already explained well here, all income is subject to TAX, I don't know how the banks in India handles incomming transfers, anyway, if the TAX authorities make a investigation on you they will ask question to every single transaction on your bank account.
If you have a high volume / huge amount of money you should consider to make a legal offshore setup where it is possible to avoid any troubles with the tax authorities. This also applies for all other countries for instant in Europe.