how much do I have to have in my bank account statement to present @ the embassy after my tuition and accomodqtion has been paid?

If you try to apply for X1 and your source of funding is self-supporting, you need to offer an original guarantee letter and latest six months bank statement of account with at least 6 million Naira in deposit from the applicant's sponsor your country.

If you try to apply for X2, original guarantee letter and latest six months bank statement of account with at least 4 million Naira in deposit from the applicant's sponsor.

m going for undergraduate course will d 4million will cover tuition +accommodation and others

Yes, you are right. You can try to contact the embassy directly as they have final day to your application. So ask the officers directly if you have more questions.