How to begin with step 1 : Getting a list of stocks ?

Hello Sir,
These are around 2000 securities listed with NSE while around 4000 securities are listed with BSE. As I have started putting effort towards fundamental analysis of stocks to look for a multibagger in a timeframe of around 10-20 years, I need some valuable advice from you. As a starting point ,I want to start from a bigger list and then narrow down my list to a point where going through annual reports of all the narrowed stocks is not an impossible task although this process might take months. During the Initial stage I found out that BSE has a better way of organizing the stocks compared to NSE.
If I visit this page ( , I can download the list of all the active companies listed in BSE .There is a field named "group(A,B,IP,M,MT,P,R,T,X,XT,Z,ZP)".I need help with this field .
Which group of companies should I not keep in my list based on the group. I hope you can share some thoughts on this.

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