Columns in 'invigilators' table:
Array
(
    [0] => id
    [1] => name
    [2] => contact_no
    [3] => inv_no
    [4] => alloted_tieup
    [5] => qualification_id
    [6] => address_one
    [7] => address_two
    [8] => address_three
    [9] => pincode
    [10] => state_id
    [11] => district_id
    [12] => type
    [13] => account_no
    [14] => account_holder_name
    [15] => bank_name
    [16] => branch_name
    [17] => ifsc
    [18] => pan_no
    [19] => aadhar_no
    [20] => created_at
    [21] => updated_at
)