Need some specific info reg montessori cum ICSE schools

Iam planning to put my DD in a ICSE school in chennai and here are my questions

1.Im from matric and my cousins studied in CBSE.I read a lot about ICSE and liked their way of teaching and thought of putting my DD in ICSE.Since i do not know anyone in my friends or relatives circle who has joined their kids in ICSE i would like to know from parents here in IL-how do you feel after your kids joined ICSE school and how satisfied are you with your decision?

2.Iam kind of inclined towards joining DD in Abacus Montessori or Navadisha but iam also concerned about their montessori way of teaching till 5th class-so by the time a child completes 5th class will he/she knows everything that a regular 5th class student will know like fractions/basic science to name a few?

3.How about joining my child in ICSE syllabus right from her kg?

Parents of children studying in ICSE schools,please provide me your inputs.

 

No response.Im sure there are lot of IL's with their kids studying in ICSE.Could you please give me your input