Get composition scheme query

No, For fresh registration under the scheme, intimation in FORM GST REG- 01 must be filed. 

Pls explain me whole process

Or send some link where I can read

I am confused how to apply for composition

You have to fill Form GST REG-01 for it.

So in dat do we have composite dealer option ?

Yes you have

(1) Any person who has been granted registration on a
provisional basis under clause (b) of sub-rule (1) of rule 24 and who opts to pay tax under
section 10, shall electronically file an intimation in FORM GST CMP-01, duly signed or
verified through electronic verification code, on the common portal, either directly or
through a Facilitation Centre notified by the Commissioner, prior to the appointed day, but
not later than thirty days after the said day, or such further period as may be extended by
the Commissioner in this behalf:
Provided that where the intimation in FORM GST CMP-01 is filed after the
appointed day, the registered person shall not collect any tax from the appointed day but
shall issue bill of supply for supplies made after the said day.

(2) Any person who applies for registration under sub-rule (1) of rule 8 may give an option
to pay tax under section 10 in Part B of FORM GST REG-01, which shall be considered
as an intimation to pay tax under the said section.