Edit: Oh **** i just read you have already spend 70k on the car, wish you had posted this before spending, i think your mechanic might be taking you for a ride (making a kaddu out of you, if you know what i am saying)
If there are cracks on the belt i would advise you to get it changed as it is the main element driving everything in your car, the price difference between original and local is HUGE, original one is for 4500 while the local/china/desi is for 400 ... yes you read that right 4k vs 400 lol
Normally after rains this chir chir noise is common with greesing it should go away but get it checked, don't get the whole car apart for that sound because source of that sound is the belt nothing else