Is is mandatory to open Capital gain account ?

No, unless you wish to get exemption under sec. 54 IT act, no need to deposit the amount in CG sav acc.

Thanks Rambhia sahab

Most welcome.              

The Buyer has deducted 1% TDS and paid online under minor head 800 (TDS OF SALE OF PROPERTY).

Whether it will reflect directly in my account or CA has to connect that TDS to my PAN?

Form 26QB is an internet based PAN challan( minor head 800) containing details of buyer, Seller, property being sold, sale consideration, tax deposit details etc.

So, if seller's pan is correctly filled in form 26QB, it will definately reflect in your AIS & form 26AS. Ask buyer to issue TDS deducted certificate, i.e Form 16B.