Query regarding Bracket Order

Suppose Reliance"s CMP is at 908 at 9.15am. But I want to purchase at 900.SO I placed a BO(Bracket Order) at 900. Now, will that order be executed at CMP or the price what I defined at 900??

Will executed @ 900 or below

But someone was telling that in Zerodha Bracket Orders gets executed at Market Entry Bracket Orders not Limit Entry

No! You can specify limit in bracket order and in your case it will be executed only when the price reaches 900

90% Your order will execute at Price 900.
But 10% Possibility that you may get Average price of say 899.85 or 899.95

Limit Entry only works if your entry is below CMP for buy orders and above CMP if it is a sell order.