here is the story,
  ma ebay ma kam gardai chhu as a consultant, uni haru le malai full time position offer garirako chha after sade 1 barsa, tara ma confuse chhu yo offer linu ki nalinu bhanera,  reason, ebay le GC processing ekai choti garidincha bhanera guarantee leko chaina, they will after some time but not now...

tara mero dhoti company have filed for my LCA, jun file gareko its more than 3 mths, tara aile samma kehi feedback aako chaina, 
I told my HR department (mero client side ko) ki mero company le mero GC ko lagi processing garirako chha, tara ma sure chuina,,how long it  is going to take...

I am confused...I don't want to miss an opportunity to be a part of this huge e-commerce company, sabai kura ramro chha..tara bas GC le adkirako chha...

and if i say "yes" today, they will start h1 transfer garne process...

Please suggest! 

should I join my client as a full timer or should I wait for my dhoti consultancy to get back to  me with feedback from DOL.

Here is my suggestion but to follow or not to follow is your choice.
First of all, under which category your labor was filed, EB2 or EB3. If it was EB3, change the company immediately because It will take lot of time. If it is EB2.
Since they already started your labor and It has been already 3 months,If I were you, I would for wait for another 1 month and check to see if labor get approved or not.
if you labor got approved then it will just ttake about 6 month to get GC (assuming 140((Premium) and 485 concurrent processing).
After you get your GC, you can join any company as you want.

Big companies like ebay.com do not file GC immediately and you have to wait atleast for a year to start the process.

I would care for GC first because that is the main thing which we should consider first. Job sob bhaneko ta testai ho..kaile lay off..kaile promotion ..testai ho..First of all you need to make your a$$ secure ..haina ta sathi? Best of luck :)

Thank you @ihateAmerica

 They have filed my LCA under EB2, and when I asked them about the status, they said it is still pending, but they also told me that if my LCA is approved , they are not going to file for my  140 immediately, they said it will take atleast a year and half..

I am more confused...

First for all, it is not LCA it is called Labor or perm. LCA is very simple and it is applicable to H1b.
I am not sure why they are not willing to file 140 immediately after labor approval. Mine was filed 15 days after labor got approved.
So here is the deal, ask them again to file 140 after labor approval. If they don't agree, check with Ebay to see if they are willing to file I-140 after you joined as Full time. If they say yes, then I would suggest you to join Ebay.
The consulting company just want to be with them for long term. That is the reason why they are not willing to file I-140 immediately.
Best of luck