Getting IndexError

[Krishna1997]

I am using this model for similar data except that our images contain Sanskrit words. I created the train, val , test files similar to the ones(i.e image_name followed by ordinals for characters) used in this model.
But in our case, the number of characters(i.e n_classes) is 118(instead of 95 in original one) and y_max_len=200(instead of 50 in original one).
When I train the model , I am getting the following error

loaded 25996 samples from ./dataset/train_img_list.txt
loaded 756 samples from ./dataset/val_img_list.txt
building symbolic tensors(0.84720993042)
('#Train samples: ', 25996)
('#Val samples: ', 756)
('#Train Iterations: ', 406)
('#Val Iterations: ', 11)
setting parameters(0.848186016083)
('n_classes: ', 118)
('multi-step: ', set([40600, 71050, 60900]))
building the model(0.848335027695)
Subtensor{int64}.0
Shape.0
computing updates and function(1.2518889904)
using normal sgd and learning_rate:0.00999999977648
('bw_lstm_b', <class 'theano.tensor.sharedvar.TensorSharedVariable'>)
('fw_lstm_W', <class 'theano.tensor.sharedvar.TensorSharedVariable'>)
('fw_lstm_U', <class 'theano.tensor.sharedvar.TensorSharedVariable'>)
('fw_lstm_b', <class 'theano.tensor.sharedvar.TensorSharedVariable'>)
('bw_lstm_W', <class 'theano.tensor.sharedvar.TensorSharedVariable'>)
('bw_lstm_U', <class 'theano.tensor.sharedvar.TensorSharedVariable'>)
('hidden_b', <class 'theano.tensor.sharedvar.TensorSharedVariable'>)
('hidden_W', <class 'theano.tensor.sharedvar.TensorSharedVariable'>)
building training function(2.72188806534)
building validating function(25.7086689472)
begin to train(27.9824080467)
.epoch 1/200 begin(27.982)
[prefetch]height: 150, x_max_step:900.0, y_max_width:200
Traceback (most recent call last):
File "train/train.py", line 148, in
loss = train()
File "/usr/local/lib/python2.7/dist-packages/theano/compile/function_module.py", line 898, in call
storage_map=getattr(self.fn, 'storage_map', None))
File "/usr/local/lib/python2.7/dist-packages/theano/gof/link.py", line 325, in raise_with_op
reraise(exc_type, exc_value, exc_trace)
File "/usr/local/lib/python2.7/dist-packages/theano/compile/function_module.py", line 884, in call
self.fn() if output_subset is None else
File "/usr/local/lib/python2.7/dist-packages/theano/gof/op.py", line 872, in rval
r = p(n, [x[0] for x in i], o)
File "/usr/local/lib/python2.7/dist-packages/theano/tensor/subtensor.py", line 2173, in perform
out[0] = inputs[0].getitem(inputs[1:])
IndexError: index 121 is out of bounds for axis 2 with size 119
Apply node that caused the error: AdvancedSubtensor(Reshape{3}.0, SliceConstant{None, None, None}, InplaceDimShuffle{0,x}.0, <TensorType(int32, matrix)>)
Toposort index: 463
Inputs types: [TensorType(float32, 3D), <theano.tensor.type_other.SliceType object at 0x7f6a4d6d9510>, TensorType(int64, col), TensorType(int32, matrix)]
Inputs shapes: [(900, 64, 119), 'No shapes', (64, 1), (64, 200)]
Inputs strides: [(30464, 476, 4), 'No strides', (8, 8), (800, 4)]
Inputs values: ['not shown', slice(None, None, None), 'not shown', 'not shown']
Outputs clients: [[Reshape{2}(AdvancedSubtensor.0, MakeVector{dtype='int64'}.0), Shape_i{2}(AdvancedSubtensor.0), Shape_i{1}(AdvancedSubtensor.0), Shape_i{0}(AdvancedSubtensor.0)]]

Backtrace when the node is created(use Theano flag traceback.limit=N to make it longer):
File "train/train.py", line 84, in
mid_layer_type = BLSTMLayer, forget=False)
File "/misc/me/rohits/aaron-cnn-lstm-ctc/layers/net.py", line 40, in init
blank = options['blank'], log_space = True)
File "/misc/me/rohits/aaron-cnn-lstm-ctc/layers/ctc_layer.py", line 25, in init
self.log_ctc(labels_len_const = labels_len_const)
File "/misc/me/rohits/aaron-cnn-lstm-ctc/layers/ctc_layer.py", line 94, in log_ctc
x1 = self.x[:, T.arange(n_samples)[:, None], self.y]