Software development is generally treated as a profession, not business, and hence is not eligible under Section 44AD. Instead, it may fall under Section 44ADA if provided by an individual or partnership firm (not LLP). However, since your firm is a 100% EOU registered with SEZ, and you’re a partnership firm, presumptive taxation under 44AD is not applicable. You should file ITR-5, not ITR-4. Also, since you're maintaining books, it's better to disclose full profit and loss and balance sheet. Consult your CA for accurate classification, as wrong filing may lead to scrutiny or penalty.