Had you opened NRE account you could have saved Income Tax on the interest earned on the remittance. You have lost this facility, apart from this there is no penalty. From NRE account, if you to repatriate money to any other country, it is easy, no permission is required.Now you cannot do.

I was working in india. My company sent me to UK 3 years ago. I used to send money to india frequently. I thought I have proof for my source of income, that should be sufficient. I recently came to know about it is illegal to have a normal bank account india, I should have converted that to NRE account. In a blog I read that there will be some penalty for sending the money to normal account. Does anyone know how much the penalty is? and how to make all the money I sent to india as legal?