Feel free to play with this tool: https://splunk-sizing.appspot.com/
Besides that, answering your question about your need is not a simple task as it may require a full architecture analysis for the ideal solution
can you kindly elaborate?
how much data do you index every day? how many users do you have? how many concurrent searches? are your indexers clustered? are your search heads clustered?
Thank for your response, here i want to know how we will figure out, how many SH, indexers we required for our environment. PLEASE TRY TO UNDERSTAND I AM VERY NEW TO THIS TOOL.