connecting two power transformer in parallel

Check the 3-phase grouping connections of the PTs. May be one of the PT grouping connection is reversed.

Star point of PT should be identical,check connection of star point of PT.If not identical then reverse start point.

Has this same reading occured at Y and B?

yes it reads around 220volts for one of phase and 110 votls for other two phases for Y and B phase

Forget about phase rotation, two transformers can have both their phase rotation in the same direction but still be out of phase.

Using a HT tester verify that the voltage between R on TX #1 And R on TX#2 is = TO 0 volts, do the same to the rest of the phases.

A safe way to do it is to conect your HT tester to another phase and confim that the Voltage does increase. (Just To confirm that the tester is OK.)

Caution if you connect these TXs in parallel with out being in phase.....BANG !!!

Your Main Xformers may be of identical ones, are your PTs identical? Check PTs Vector Groups.

That is what I have said in (1) above.

thanks for the helping me , but i am surprised that same thing i have checked in LT system ie in 11/0.420KV,when i connected a double test lamp across LT side of two transformer(for both tfr's input source is same ie from diesel generator of 10MW) R-phase and i found test lamp glows bright and voltage measured around 486volts (both tfr's are of same make and same vector group ie Dyn11) and that to other phases it reads 220volts so then i changed input side connection of one transformer and checked found double test lamp across R-phase of one tfr and R-phase of another LT side not glowing so i got Wat i needed but didn't understand how it could happen so plz help me for this also