sorry for forgetting to answer the 2nd part.
What State Govt. follows is that, admissible amount equal to the actual expenditure or expenditure for carrying 6000 kg whichever is less. Generally actual expenditure is higher considering other incidental charges (transportation charge from home to station), then an additional expenditure of less than 25% of the maximum admissible amount i.e. for 6000 kg may be granted.