Input tax credit

yes if it's used for business

can we ITC of car insurance

You cannot claim itc on motor vehicles and other conveyances except when they are used––
(i) for making the following taxable supplies, namely:—
(A) further supply of such vehicles or conveyances ; or
(B) transportation of passengers; or
(C) imparting training on driving, flying, navigating such vehicles
or conveyances;
(ii) for transportation of goods;

what about GST we pay on insurance premium.Can we claim ITC?

If it is being used in above said condtion , yes u can claim ITC on its repair

section 17(5) contains the word 'in respect of' therefore credit shall not be available on repair of motor vehicles. 

however if you are using vehicle for transportation of goods u can claim itc for such repairs.