Dear All.,
im writing a flow service, in that i want a branch llike:
1: ill get a Value from my map —say it 100
2: now i want to check this 100 will be placed at where

It sounds like the question is as follows:

1. do something to get a value (say maxRecords = 100)
2. check the contents of maxRecords
3. if maxRecords = 100, map it to field X

How to accomplish this:

1. you have maxRecords = 100
2. map maxRecords to the destination element (string, etc)
3. double click the line connecting the two elements (for a conditinal map)
4. in the ‘map only if’ section, type maxRecords=100

it sounds like it’s not really a question

nor an answer…

You can you the branch to evaluate labels

BRANCH (evaluate label: true)
SEQUENCE (label: %maxRecords% == 100)
… more flow
SEQUENCE (label: $default)
… more flow

So the evaluation of the label is in the sequence step or the label of any step.
Although I don’t see why this won’t work and would be preferred.

BRANCH (evaluate label: false, switch: /maxRecords)
SEQUENCE (label: 100)
… more flow
SEQUENCE (label: $default)
… more flow

Good luck.

The Developer Programming References explain this as well as active help through the developer itself. For the later I think you can press F1 key when you have selected an inserted branch step. Finally looking over the regular expression information in the former help section will be helpful for future solutions you create.