Maintaining balance sheet

It's always good to maintain balance sheet as you are doing business and in case of any query raises by any department in future, you will be able to defend yourself in a more structured manner. In case, you are filing ITR U/s 44AD, then balance sheet is not required but data of few items of balance sheet are required. So, it is recommended to maintain balance sheet and all other related documents, vouchers which substantiates that balance sheet. Better hire a professional person if you can't manage the entire thing.

Is it good to maintain accounts in tally and do the reconcillation of bank statement in order to maintain balance sheet?

Yes you can do

is it neccessary to record actual expenses in balance sheet for eg electricity expenses,telephone expenses,office expenses etc
or can we predict from last year itr form and change figures and then show it in current balance sheet.

Balance Sheet as on a particular date depicts the financial position of the Person on that date which must be true from all aspects. If you use imaginary figures to prepare the same, leave the statutory departments, you on your own will not understand the true picture of your business. And, further if you fail to substantiate your imaginary figures in front of any departments, you will be penalised accordingly. So, it's always recommended to prepare balance sheet with actual figures. You can put imaginary figures for a particular expense only when you don't have any documents/vouchers/records with you for the same and that too you have to put on the basis of systematic guess.