How to join a governement job while already working in a government job ??

Respected sirs , I would like to state my condition clearly so as to get expert advice on my problem . During first/second week of january 2020 I came to know that I have been selected as assitant grade 3 ( accounts stream ) in FOOD CORP. OF INDIA ie F.C.I. then after a few days I came to know that I have been selected in LIFE INSURANCE CORPORATION ie L.I.C. , now LIC process is fast and I have got my documents verified and after a few days my medical exam is going to be done and most probably in first week of February LIC will give me posting and further joining . My problem is that FCI is slow in this regard . I have no idea of its Documents verification dates and A few people working in FCI told me that you will not know about the posting place unless you join the FCI . In LIC I will be posted within 100-150 kms away from my home( mirzapur , uttar pradesh ) but in FCI posting can be given in PUNJAB and HARYANA . I want to know if there is any way by which I could resign from LIC on a condition that I could join LIC again within a stipulated time like 3/4 months. Please help me out of this situation .