Dear bro,
U can do as per below:
"Reference letters in the required format are necessary, please try your best to get them. If after all efforts you are unable to obtain a work reference letter, then you should provide a solemn declaration / affidavit explaining in detail why are you unable to do so. The officers at the VO are aware of the fact that different employers have different policies towards issuing such adhoc letters and may not cooperate in issuing such a letter. Please do attach all your employment records with the declaration. I was unable to obtain a work reference letter from one of my employers and did the same. However please bear in mind that the final decision rests with the visa officer handling your case."
And for any NOC u can assume atleast ---one month