1. There is nothing wrong in filing a loss return with respect to a partnership firm.
2. Sec 44AB mandates tax audit if the gross receipts or T.O during the year exceeds Rs. 1 crore or otherwise a person has for presumptive taxation u/s 44AD or sec 44ADA.
3. If you look into sec 44AD, it is an option given to the eligible assessee to opt for such a scheme to avoid the hardship for maintaining books of accounts and other compliance aspects.
4. Sec 44AD is nothing but an optional scheme and assessee have the right to either opt for it or to pay tax under the regular scheme.
5. So in your case, it is not mandatory for you to opt for presumptive taxation scheme u/s 44AD if the T.O is less than Rs. 1 crore.
Please correct me if the above solution has an alternative view.