@Adnan read and review some articles from the Gurus in the area. You may search these articles from reputable research platforms like Research Gate, SSRN google scholar etc. Another simple way to get a possible research gap is to create a meaningful interaction among the predictors ( Mediation or moderation)
Of related subjects should focus on just one. I think that evaluating the performance of institutions is an excellent idea. Look for information on Data Envelopment Analysis (DEA) to evaluate the efficiency (performance) of institutions.
The main problem of Micro Finance companies, is the lack of public and standardized information. This has always been a great limitation.
Additionally there are several other factors. An estimate of debt and equity based on the balance sheets of an MSE also represents limitations. On the one hand, the assets reported by the MSEs tend to be undervalued because they do not include the owner's personal guarantees, which are required by credit institutions.
In addition, small entrepreneurs obtain non-pecuniary benefits, not recorded in the accounting books, such as the enjoyment of independence and maintaining family ties (Ang, 1992).
Ang, J. S. (1992). On the Theory of Finance for Privately Held Firms. Journal of Small Business Finance: Vol. 1: Iss. 3, pp. 185-203.
there is the issue of agency problem whereby the companies focus on improving the performance of the firms without considering the issues between management and shareholders. this is a gap which needs to be researched to enable the companies not only to focus on performance rather than the issues between management and shareholders.
I thought it is complicated one. We've to compare governance and capital structure but in case of micro financial institutions we have to find the gap is very rare.