Once the requirements are baselined then only we can go for 
testing the application.
if it is wrong plz.correct me

once we are getting the requirements from client immediatly 
we start the testing process.then we can approch diffent 
style  that means that is depends up on organization.

Well testing in a project can be started in two ohases.
They are 1) Conventional testing
         2) Unconventional testing

Conventional testing starts after the coding part in the 
SDLC. Here the functionality of any pertiucular application 
is being tested.

Unconventional testing starts right from the first ohase of 
the SDLC. Here the functionality is not being tested but 
all the documents that come out in each phase are tested 
that is BDD-initial
        SRS-Analysis
        TDD-Desing
        SCD-Coding etc...
Hope its the right answer.
Please suggest if any changes can be made.

As per the principal of software testing, the testing 
should start from the initail stage of Software Development 
Life Cycle(SDLC). We should verify every stage of SDLC, 
whether it is Requiremwnt gethering Stage,Design stage or 
coding stage..... verification(testing) is required at 
every stage of life cycle to deliver Quality software to 
the Client.

Once the requirements are frozen then we will writing the 
test cases

As soon as we have a software requirement(baseline).

whenever we get a requirements than we can start a testing.