Teaching job offer from a Pakistani School? please help and guide me???????

dear all,

i got an offer from a pakistani school. they are saying that my probition period will be 03 months or may be extend to 06 months.
but in offer letter they are mentioning that no need to give resign from your existing job and take leave for two or three months. after probition at that pakistani school then i have to submitt my resign from existing job.

my worry is that some of persons are saying that this is their habit and after every three months they are appointing new fresh teachers with less salaries.
i am a qualified teacher with Master of Education and M.sc and having 10 years teaching experience so i m not worry about my performance during probition period.

can anybody have the same experience ,please let me know because i have to adjust my two sons before joining at there. as my elder son is studying in other school and younger one i will put in baby sitting centre.
kindly help me to decide on this matter.