If the partnership deed is silent on interest on capital, then:

NCERT (2026-27 edition):
Provisions of Partnership Act Relevant for Accounting – “… (b) Interest on Capital: No partner is entitled to claim any interest on the amount of capital contributed by him in the firm as a matter of right. However, interest can be allowed when it is expressly agreed to by the partners. Thus, no interest on capital is payable if the partnership deed is silent on the issue.”