Good higher secondary school recommendations

So, it's almost that time of the year again. I want my sister to get into a good school for 11th and 12th and I kinda prefer CBSE. Currently she is in Carmel state syllabus. I myself passed out from St Thomas CBSE in 2019 and it was alright at that time. But I hear it's not as great now, especially with the current management. What are y'alls thoughts, experiences and recommendations? Thanks in advance