While the selection process for admission to IIM Indore and IIM Shillong varies from year to year and depends on various factors such as the number of applicants, the quality of the applicant pool, and the cut-offs set by the institutes.
It is generally considered challenging to secure admission to these institutes with a 92 percentile in the Common Admission Test (CAT) as a general category student. But if you are from the EWS category then it is not that difficult. Also, the CAT percentile is just one of the criteria that are considered for admission to IIMs, institutes also take into account several other factors such as academic performance, work experience (if any), and performance in the Written Ability Test (WAT) and Personal Interview (PI).
If you have a strong academic record, try and perform well in the WAT-PI, and if you are able to demonstrate your potential for academic excellence and leadership, then you have a good chance of securing admission to IIM Indore or IIM Shillong.