Help and advice needed

Respected all,  I have joined DRDO as STA-B (group c non- ministral ,non-gazetted)in May 14.before joining I ve cleared written exam and appeared for interview for the next batch of same post.result was not out then.now i have cleared this time also and my posting is at a better place(bangalore).in this case can i resign and rejoin??(same govt dept and same post)can DRDO Refuse my rejoining after i resign on personal grounds.thank u in all advance .