40(b) deduction and 44AD

Yes, it can claim deduction from 8%/6% profits under section 40(b) subject to maximum limits

Is any provision

You can refer section 44AD
it's mentioned in section that
44AD(2) Any deduction allowable under the provisions of sections 30 to 38 shall, for the purposes of sub-section (1), be deemed to have been already given full effect to and no further deduction under those sections shall be allowed :
[Provided that where the eligible assessee is a firm, the salary and interest paid to its partners shall be deducted from the income computed under sub-section (1) subject to the conditions and limits specified in clause (b) of section 40.]