Do we have to show all non GST supply (Salaries, Electricity , etc.) in GST Return?

I have been filling under form-k(in the old portal ctd.tn.gov.in) until June2017. In GST Portal i have forgot to opt in for composition scheme. We have also already issued invoices(bill of supply) under composition scheme for July. its difficult for me to cancel the bills already issued. How should I proceed ? 

if we paid gst under rcm cash. now can we take itc of this in the gstr 3b if july month

I am a small coaching class owner earlier registered for Service tax. I was filing nil return as my turnover is less than 10,00,000. My consultant told me that i have to first migrate to GST and then cancel the registration and with that intention i registered for GST now please answer my queries
1 It seems that I have wrongly registered for GST, as my Turn over is less than 20,00,000. When and how can I cancell my registration under GST.
2. When there is a wrong registration, then do I am suppose to file returns?
3. Can I file NIL return?
4. What if I did not file a return, as no GST is collected and it is a wrong registration.
Manoj Muley

1.what is the use RCM. why we pay and get back as ITC. 2. SHALL WE PAY GST AFTER SUBMITTING

if a dealer issued invoice with gst but gst registration no. has not been issued .what is the solution for this problem

Iam exporter, IGST payable is Rs.150000 and ITC available Rs.350000. and we receiving Duty drawback and ROSL (State Leavy) against our export sales. which is giving by central govt up to sep17 with condition of No refund will be claim in our state due to state Leavy availing by us. In this case can we adjust IGST payable in to ITC (Contain both CGST & SGST).? pls clarify.

Dear Sir We are exporters of services which should be treated as ZERO returns and has to file under (b) Outward taxable supplies (zero rated ) but I submitted under (C) Exempted. Can you help me with this if we can rectify while filing GSTR 3 ? "

If i have an liability of reverse charge in july and i pay it off in that month when will i get the ITC of reverse charge

Where Repair charges involved in a jewellry belonging to customer amounting to 2 gram given by customer wherein another 2 gram has been put by jeweler, wherein jeweler raised bill for 2 grams and repair charges.Whether under composition 3% GST is okay?