NOC
My company agreed for VISA transfer to other company once I submit the Offer letter of the new company. the question is once I join the new company, how much time should I work to get changed to other new companies in case, then automatically will I get the NOC as they have recruitted me locally. please suggest or does it depends on the boss.
2 years with a company - that's the rule for change of sponsorship
NOC - totally at a discretion of your company (I hear there are planned changes to the sponsorship law, but I wouldn't bet on it)
most companies issue NOC for a 'local hire', but still - a lot of them will not issue NOC at all.
if you're not sure about your new job - my advise would be don't take it - wait for something that you're absolutely sure about because you'll be stuck with it for 2 years... and maybe longer!