A Chartered Accountant is a full fledged professional and apart from small competency shots, we don't need the support of any other degree to get us a certain profile.
To answer your question, "do a fresh CA is required to hold certificate in sap , i mean if i do a course which provides traning and overview of sap but not an official certificate by any institute will it be ok?"
No, A CA is not required to hold SAP certification to be an SAP consultant. But yes if you want to increase your competency, any institute will be ok for that matter. I am not SAP certified myself and I didn't go for any SAP exposure before getting into this profile. The company itself gave me internal training in SAP FI and CO and I have been doing fine.
"icai have come with a couse on sap fees for which is Rs. 147500/- details about the same is as under ,i dont know whether to do it from icai bcoz another private istitue is offerring me the course at Rs. 50000/- what should i do?
See, there is a major gap in the details. This institute which is charging you 50,000, I am not sure wheather it is providing you certification or just SAP project exposure. ICAI will surely provide you certification. Because there are two types of institutes involved in SAP coachings... first those which are SAP authorised and they charge around 3 lacs for the coaching, study material plus certification exam fee.... Second there are institutes who only give you SAP knowledge through classroom and lab training, but they are not SAP authorised so they can't provide you certification nor you can yourself sit for certification exam (because for sitting in certification exam yourself by filling up the exam form without any institute, which costs around 35,000/- only, you need one year's SAP experience as a consultant or as an end user and you have to show it).. and these institutes charge you from 30,000 to 50,000/-.
Do your research and decide what you want to go for. Prior SAP exposure will certainly give you an edge in the interview.