hi rakeshyadavfmcg,
the minimum amount required for 'maintenance funds' is £800 that should be there in the account for the last 3 months as per the UKBA rules as of now.
Minimum £800 is for Tier 1 PSW and Minimum £1200 is for student visa extension.
this information can be found at:
http://www.ukba.homeoffice.gov.uk/worki ... intenance/
This amount was there for atleast last three months is supposed to be proven by showing your bank statement (it is one of the requirement) with the other required documents when you send in the application form.
answers above are according to the current rules.
Thanks.